rivers of Siberia. Several distinct species occur in the lakes of Sweden; a few are found in the lakes of Switzerland and central Europe. C. hiemalis is peculiar to the Lake of Constance. Several species inhabit the great freshwater lakes connected with the river St Lawrence of North America, and the lakes farther to the north. One of these is cultivated by the American Fish Commission :

Coregonus clupeiformis, Mitchell, Dekay (New York Fauna, Fish), Cuv. and Val., Agassiz (Lake Superior) (the Shad Salmon, Freshwater Herring, Whitefish). D. 12; A. 14; L. lat. 76-77; L. transverse f The snout is pointed, and there is an appendage to the ventral fin which is half as long as the fin itself. Length of adult 11 to 13 inches. Lakes Erie and Ontario.

then deposits her eggs in the trough; while she is engaged in these operations she is attended by a male, who sheds milt over the eggs as the female extrudes them, fertilization being, as in the great majority of Teleostei, external. The parent fish then fill up the trough and heap up the gravel over the eggs until these are covered to a depth of some feet. The gravel heap thus formed is called a "redd." The period of the year at which spawning takes place in the British Isles, and in similar latitudes of the northern hemisphere, varies to a certain extent with the locality, and in a given locality may vary in different years; but, with rare exceptions, spawning is confined to the period between the beginning of September and the middle of January.

Thymallus aliani, Cuv. and Val. (06μaλλos, Æl., xiv. 22), occurs in Lago Maggiore. One species has been described from Siberia, and two are known inhabiting Lake Michigan and the waters of British North America,

5. Of Argentina four species are described in the Brit. Mus. Cat., namely:-Argentina silus, Nilsson, occurring off the north-west coast of Norway, Argentina sphyræna, L., from the Mediterranean, Argentina hebridica, Nilsson, found on the coasts of Norway and Scotland, and Argentina lioglossa, Cuv. and Val. According to Mr Day, two of these, A. sphyræna and A. hebridica are identical, the species ranging from the coast of Norway and east and west shores of Scotland to the Mediterranean. The following is the formula of A. hebridica, Nilsson, according to Günther:-D. 9-11; A. 18 (12); P. 13-14; V. 11; L. lat. 52-53; Cæc. pyl. 14-20; Vert. 52. The scales with minute spines.

6. The species of Oncorhynchus are all anadromous, and are confined to American and Asiatic rivers flowing into the Pacific. O. quinnat, Richardson O. chouicha occurs in the river Sacramento, and is cultivated by the American Fish Commission.

7, 8. For Brachymystax and Luciotrutta, see p. 221 above. 9. Plecoglossus comprises small aberrant freshwater species abundant in Japan and the island of Formosa.

10. Retropinna contains but one species, R. richardsonii, which is known as the New Zealand Smelt. It is cominon on the coasts of New Zealand, ascending estuaries. Like Osmerus eperlanus, it is landlocked in fresh water in some localities.

11, 12. The species of Hypomesus and Thaleichthys occur on the Pacific coast of North America. Thaleichthys pacificus, Girard, is caught in vast numbers in the neighbourhood of Vancouver Island; it is extremely fat, and is used as a torch when dried, and also as food. It is called locally the Eulachan or Oulachan.

13. Of Mallotus only one species is described by Günther:Mallotus villosus, Cuv. and Val., Müll. (the Čapelin; French, Capelan). B. 8-10; D. 13–14; A. 21–23 ; P. 18–20; V. 8; Cæc. pyl. 6; Vert. 68. Brownish on the back, silvery on the sides. Operculum silvery with minute brown dots. Shores of Arctic North

America and of Kamchatka.

14. Of the genus Salanx two species are known:-Salanx chinensis, Günther, Osbeck, which is common on the coast of China and called "Whitebait" at Macao, and Salanx microdon, Bleeker, from the rivers of Jeddo.

15. Microstoma.-M. rotundatum, Risso, is marine and occurs in the Mediterranean; it is not anadromous. It is the only species of the genus known, unless the Microstomus grönlandicus, described by Reinhardt, from the Sea of Greenland, really belongs to this genus.

16. For Bathylagus, see p. 222 above

Life History of the Salmon and Allied Species. Up to a period not many years past, when our knowledge of the breeding and life history of the salmon and kindred species was based entirely on desultory observations of the fish in their natural conditions, there existed a great deal of uncertainty and diversity of opinion on the subject. Within the last twenty or thirty years the extensive practice of sulmon culture has removed nearly all obscurity from the phenomena, and the history of Salmonoids is now more accurately known than that of most other fishes.

The salmon proper, Salmo salar, breeds in the shallow running waters of the upper streams of the rivers it ascends. The female, when about to deposit her eggs, scoops out a trough in the gravel of the bed of the stream. This she effects by lying on her side and ploughing into the gravel by energetic motions of her body. She

a quarter of an inch. It is usually estimated that a female salmon produces about 900 eggs for each pound of her own weight; but this average is often exceeded.

The time between fertilization and hatching, or the escape of the young fish from the egg-membrane, varies considerably with the temperature to which the eggs are exposed. It has been found that at a constant temperature of 41° F. the period is 97 days; but the period may be as short as 70 days and as long as 150 days without injury to the health of the embryo. It follows therefore that in the natural conditions eggs deposited in the autumn are hatched in the early spring. The newly hatched fish, or "alevin," is provided with a very large yolk-sac, and by the absorption of the yolk contained in this the young creature is nourished for some time; although its mouth is fully formed and open, it takes no food. The alevin stage lasts for about six weeks, and at the end of it the young fish is about 1 inches long. During the next period of its life the young salmon is called a parr," and is distinguished by the possession of a number of dark transverse marks along the sides, known as parr marks." These marks occur in the young stage of many species among the Salmonida. The parr doubles its length in about four months. The great majority of parr remain in fresh water for two years after hatching, at the end of which time they are about 8 inches in length. The second spring after they are hatched they develop a coating of bright silvery scales which completely conceals the parr marks, and they pass into a stage in which they are known as "smolts." The smolt is similar to the adult salmon in all respects except size, and the young salmon, as soon as the smolt stage is reached, migrates down the rivers to the sea.

་

The above facts have been established within recent years by accurate observation and experiment. Not very long ago it was a disputed question whether the parr was the young salmon or a distinct species of fish. That the former view was correct was first experimentally proved by Mr John Shaw, gamekeeper to the duke of Buccleuch, Drumlanrig, Dumfriesshire, who in 1888 isolated several parrs in a pond, and found that in April 1834 they changed into smolts; an account of this experiment was published in the Transactions of the Royal Society of Edinburgh. The question is now of merely historical interest, for at the present time farge num bers of parr are hatched at various fish-hatching establishments every season. By observation at these establishments, the knowledge of the history of the parr and the migration of the smolt which had been gained by the study of the fish in their natural conditions has been rendered more accurate and complete. It has been conclusively ascertained that some parr become smolts and migrate to the sea in the spring following that in which they were hatched, while the great majority remain in the parr stage until the second spring, and a few do no attain to the smolt condition until the third year. The male parr when only 7 or 8 inches in length is often sexually mature, the milt being capable of fertilizing the ova of an adult female salmon.

The migration of smolts to the sea takes place in all rivers at about the same time of the year, viz., between March and June. Sometimes the smolts are observed descending in large shoals. Formerly angling for the descending smolts was a recognized sport, but their capture is now illegal. It is the opinion of the most competent authorities that the smolts increase with wonderful rapidity in size and weight when they reach the sea, and then return to the rivers after a few months, during the same year, as "grilse," which name is given to sexually mature salmon up to a little over 5 Ib in weight. It is surprising that a smolt weighing only a few ounces should increase to 3 or 4 or even 6 tb in about three months. Nevertheless it has been proved by actual experiment that this is the fact. At Stormontfield, in May 1855, 1800 smolts were marked by cutting off the adipose fin, and 22 of these

the salmon was made at the salmon-hatchery of Stormontfield near Perth in 1862

1 The first important series of experiments on the growth and life history of

and some previous years. The results are detailed in a work entitled Stormontfield Experiments, 1862.

were recaptured the same summer as grilse, weighing from 3 Ib upwards. It might be supposed that some smolts do not return as grilse till the summer following the year of their descent, the time of their stay in the sea being variable, as is the period spent by parr in the rivers. But all the evidence is against this supposition; grilse never commence ascending till late in summer; if they had been more than a year in the sea, some would probably ascond carly in the season, as do the larger salmon. At the same time it must be borne in mind that a fish which remained in the sea a year after descending as a smolt might not be recognized as a grilse, having reached the size of a small salmon.

The grilse, after spawning in autumn, return again to the sea in the winter or following spring, and reascend the rivers as mature spawning salmon in the following year. Both salmon and grilse after spawning are called "kelts. The following recorded experiment illustrates the growth of grilse into salmon :—a grilse-kelt of 2 lb was marked on March 31, 1858, and recaptured on August 2 of the same year as a salmon of 8 lb. The ascent of rivers by adult salmon is not so regular as that of grilse, and the knowledge of the subject is not at the present time complete. Although salmon scarcely ever spawn before the month of September, they do not ascend in shoals just before that season; the time of ascent extends throughout the spring and summer. A salmon newly arrived in fresh water from the sea is called a clean salmon, on account of its bright, well-fed appearance; during their stay in the rivers the fish lose the brilliancy of their scales and deteriorate in condition. The time of year at which clean salmon ascend from the sea varies greatly in different rivers; and rivers are, in relation to this subject, usually denominated early or late. The Scottish rivers flowing. into the German Ocean and Pentland Firth are almost all early, while those of the Atlantic slope are late. The Thurso in Caithness and the Naver in Sutherlandshire contain fresh-run salmon in December and January; the same is the case with the Tay. In Yorkshire salmon commence their ascent in July, August, or September if the season is wet, but if it is dry their migration is delayed till the autumn rains set in. In all rivers more salmon ascend immediately after a spate or flood than when the river is low, and more with the flood tide than during the ebb.

In their ascent salmon are able to pass obstructions, such as waterfalls and weirs of considerable height, and the leaps they make in surmounting such impediments and the persistence of their efforts are very remarkable. In a great many rivers anadromous Salmonoids have been excluded from the upper reaches by artificial obstructions, such as dams and weirs, constructed for the purpose of utilizing the water of the stream, or to obtain water power, or simply to facilitate the capture of the fish. Other rivers have been rendered uninhabitable to salmon by pollutions. The state of the Thames within the boundaries of London has since the beginning of the present century excluded Salmonoids entirely from the river; but every season salmon and grilse are taken in or near the Thames estuary, and there is no doubt that if the water could again be rendered moderately clear, and if fish-ways were provided at the impassable weirs, the upper waters of the Thames would again be frequented by salmon and migratory trout.

The life history of Salmo trutta and S. cambricus is very similar to that of Salmo salar. The river trout, S. fario, makes a redd in the shallower parts of streams in the same manner as the salmon, the only difference being that the mound of gravel forming the redd is smaller, the egg lying from one to two feet below the surface. The breeding period of the trout varies in different rivers, within the limits of September and March.1 The number of eggs produced by each female is about 800 for every pound of the parent's weight; about 40,000 of the eggs make a gallon, so that they are considerably smaller than those of S. salar. The trout of Loch Leven, S. levenensis, ascend the streams feeding the loch, in order to spawn, at the end of September and beginning of October. The habits of other species of lake trout are similar to those of S. levenensis.

The charrs differ from lake trout in tne fact that they do not ascend streams in order to spawn, but form their redds in the gravelly shallows of the lakes they inhabit. The spawning period of the charr of the Cumberland lake district is from the beginning of November to the beginning of December. Tho eggs of the charr have been found to hatch in from 60 to 90 days, the great majority in 70 days, at an average temperature of 40° F. The American species, S. fontinalis, breeds at about the same time as S. fario; its eggs are only half the size of thoso of the latter.

The smelt, O. eperlanus, is a grogarious fish and exhibits regular migrations in most estuaries. It is common in the Solway, the Firth of Forth, the rivers of Norfolk, and the estuary of the Thames. In most places where it is found it remains in the fresh and brackish water from August until May, spawning about the month of April, and afterwards descending to tho sca for tho

The average period between fertilization and hatching, as ascertained at Howietoun, is at 44°1-Salmo farto, 71 days; S. levenensis, 72; S. fontinalis, 78: 8. salar, 77

summor. At Alloa on the Forth smelts aro taken in large numbers by scino nets in spring, before and during the spawning period. There is a regular fishery for them at the same season on the Solway Firth and in Norfolk. The food of the smolt consists chiefly of young fish, especially young herrings, and crustaceans. The eggs are small, yellowish in colour, and adhesive, not adhering by the surface merely as is tho caso with those of the herring, but each egg possessing a short thread the end of which becomes attached to planks, stones, or other solid objects in the water. According to Mr Day the eggs are deposited near the high-water mark of spring-tides, so that they must be exposed to the air during the ebb. The smelt when in the sea is largely eaten by the picked dog-fish Acanthias vulgaris). The species is absent from the southern coast of England and from Ireland, the smelt recorded as occurring on those coasts being probably the atherine (Atherina), often called the sand-smelt. O. eperlanus is abundant on the coast of Finland, and also is common there in freshwater lakes, in which it remains all the year round. It is also common on the Atlantic coast of France. It is of interest to note that the smelt in Britain and on other coasts, when not confined to fresh water, is, in its migration, intermediate between anadromous Salmonidæ, which ascend to near the sources of rivers, and such fish as the herring, which approach the shore to spawn but do not usually enter rivers. The smelt as a rule ascends estuaries only as far as the region of brackish water.

The various species of Coregonus resemble the charr in their habits, spawning in the autumn in the shallows of the lakes they inhabit; their ova are small, and, as mentioned in PISCICULTURE (q.v.), are non-adhesive and of almost the same specific gravity as fresh water, so that they are semi-buoyant.

The grayling, Thymallus vulgaris, is in Britain exclusively fluviatile; in Scandinavia it is found also in lakes. It is met with chiefly in clear streams with sandy gravels or loamy beds. It was introduced not many years ago into the Tweed by the marquis of Lothian, and thrives there. It is absent from the Thames, but is common in most of the rivers of England and Wales -e.g., the rivers of Yorkshire, the Severn, and the Wye. It is absent from Ireland. It feeds on insects and their larvæ, crustaceans, and small molluscs. It breeds in April and May, depositing its ova on the surface of the gravel in the shallows, not in a redd. The ova are smaller than those of the trout, and vary in colour from white to deep orange, and they hatch from the twelfth to the fourteenth day after extrusion. The fry grow to 4 or 5 inches in length by August, and by the following autumn to 9 or 10 inches.

Salmon Fishery Legislation.

In England and Wales the common law is that every person has an equal right to fish for salmon in the sea and in navigable tidal rivers, while the proprietors of the soil on the banks of rivers which are not navigable have the exclusive right of fishing in them. The erection of stake-nets, or other fixed engines for the capture of salmon in estuaries or on the sea-coast is necessarily incompatible with the maintenance of the public right of fishing, and has therefore from very early times been regarded as illegitimate. There has consequently been a constant conflict between legislation and private interest over this point. By Magna Charta all fishing weirs were abolished except on the sea-coast, but the object of this seems to have been rather the protection of the freedom of navigation than the advantage of the salmon fisheries or the maintenance of a public right. In later times fixed engines were repeatedly declared illegal and their erection prohibited by statute. Finally in 1861 they were definitively abolished in all cases except where legal right to maintain them could be conclusively proved. The Salmon Fishery Act of 1861, of which the prohibition just roferred to was one of the clauses, was based upon the report of a royal commission appointed in 1860 to inquire into the condition of the salmon fisheries, and it forms the basis of the regulations at present in force, all previous legislation being by it expressly abolished and superseded. It prohibited the capture of unclean and unseasonable salmon, made a uniform close season for England and Wales, ordained a weekly close season of fortytwo hours, provided for the erection of fish-passes and regulated the use of fishing weirs on non-navigable rivers, vested the central authority of the salmon fisheries in the Home Office, and provided for the appointment of inspectors. In 1863 an Act was passed prohibiting the exportation of salmon during the close time. In 1865, as it was found useless to legislate without machinery to enforce the law, an Act was passed to constitute fishery districts under the control of local boards of conservators appointed by the magistrates in quarter-sessions. These boards were empowered to enforce a licence duty on fishing implements used in public waters. One or two minor salmon fishery Acts wero passed in succeeding years, but the next important piece of legislation on tho subject was the Act of 1873, the two most important provisions of which are (1) that fishermen in public waters for every £50 of licence duty which they pay elect a member of the XXI.

29

local board of conservators, and (2) that each boara of conservators may make bye-laws for the regulation and improvement of the fisheries. within its own district. The annual close time for salmon in England and Wales at present for nets commences Aug. 14-Sept. 30 and closes Feb. 2-April 1, varying in different districts within the limits given; for rods the close time is Sept. 30-Nov. 29 to Feb. 1-May 1. The law as regards close time for fixed engines was amended in 1879. The method of fishing followed in the English and Welsh estuaries is in consequence of the above course of legislation that of sweep-nets worked from shore by boats; a licence duty has to be paid for each net, and stako-nets along the coast are very rare. An inspector of salmon fisheries appointed by the Home Office reports annually.

In Scotland the salmon fishery customs in one respect differ much from those of England: stake nets are the common and universal means of salmon capture in estuaries, although sweep nets are also employed. The reason of this is that originally all the salmon fishings belong to the crown or the grantees of the crown. The principal Acts regulating Scottish salmon fisheries are those of 1862 and 1868, but, as the previous statutes have nover been repealed, the law on the subject is somewhat confused. Scotland has been divided into fishery districts managed by district boards. An annual close time of 168 days is enforced, lasting for nets from August 26 to September 14 until February 5 to February 25, and for rods from September 14 to November 20 until January 11 to February 25. The weekly close time lasts thirty-six hours, from Saturday night till Monday morning. The construction of cruives, mill-lades, dams, and water wheels and the size of the meshes of nets are all regulated. In 1882 the management of the salmon fisheries was placed together with that of the sea fisheries under the control of the reconstituted Scottish Fishery Board, to which power was given to appoint an inspector of salmon fisheries; by this official an annual report of the condition of the fisheries is presented through the Fishery Board to the Home Office.

The principal Act relating to Irish fisheries is that of 1863. Special Fishery Commissioners are responsible for the carrying out of the legal regulations. The country is divided like England and Scotland into fishery districts under the jurisdiction of boards of conservators, by whom clerks and water bailiffs are appointed. A scale of licensing duties is enforced, and all new fixed engines-that is, any beyond those which legally existed in 1862-are illegal. The weekly close time in Ireland is of forty-eight hours' duration, from 6 A.M. Saturday to 6 A.M. Monday. The annual close time is for nets from July 16 to September 30 until January 1 to June 1, and for rods from September 14 to November 1 until January 1 to June 1. In Ireland as in England and Scotland an inspectorship of salmon fisheries exists, and the holder of the office makes an annual report to the Home Office on the condition of the fisheries.

Introduction of Species to New Areas by Human Agency. Within the past few years, since great activity has been exhibited in pisciculture generally, and especially in the culture of Salmonida, various experiments have been made in the transportation of eggs or young fry of valuable species from their native habitats to distant parts of the world. The American socalled brook trout, S. fontinalis, has been imported somewhat largely into Britain by various salmon fishery proprietors. It thrives well in various places in England, Scotland, and Wales where it has been set free,-for example, in Norfolk rivers, near Guildford in Surrey, and in the stock ponds at Howietoun.

In Nature, July 16, 1885, an account was given of the introduction of the fry of tho American landlocked salmon (S. salar, var. sebago) to the upper waters of the Thames. Eggs of S. namaycush, S. sebago, S. fontinalis, and Coregonus albus have been successfully forwarded from the hatcheries of the American Fish Commission to the Deutsche Fischerei-Verein in Berlin, and to the Société d'Acclimatation at Paris.

The common trout of Britain, S. fario, was introduced with complete success into Tasmania nearly twenty years ago by Frank Buckland, and is now abundant in the Tasmanian streams, although it is reported to be much less valued as food there than at home. From Tasmania the eggs were transported to the rivers in Otago, New Zealand, where they also thrive and breed (see Trans. of Otago Institute, 1878). In 1866 Mr Francis Day introduced the fry of the same species into the rivers of the table-land of the Nilgiris in the neighbourhood of Madras.. The experiment on this occasion failed, but two years later the establishment of the species in the district in question was successfully accomplished by Mr M'Ivor, who imported the fry from Scotland.

Salmon Cullure.

For the artificial culture of Salmonoids the reader is referred to the article PISCICULTURE. The following account of the salmon and trout hatcheries in Scotland is abridged from a paper read before the Scottish Fisheries Improvement Association in Edinburgh, 26th November 1884, by J. Barker Duncan, the honorary secretary to the Association.

The principal institution of its kind in Scotland at present is the Howletoun Fishery, belonging to Sir J. Gibsou Maitland, who cominenced it in 1873. Howfetoun is about four miles from Stirling. The establishment contains thirty-two fish ponds and a large hatching-house; there aro also four ponds at Craigend, and one of 9 acres at Goldenhove, where fish are reared to their adult condition. The hatching-boxes are of wood, and the eggs are kept during development on glass grilles. The water supply is abundant, about a million gallons of spring water flowing through the ponds every twenty-four hours. The eggs hatched in greatest numbers are those of the Loch Leven trout, but Salmo salar and the common trout (Salmo fario) are also extensively reared. The American brook trout, S. fontinalis, is also cultivated. More than ten millions of ova are annually treated at this hatchery. In 1884 ninety thousand young fish were distributed to various parts of Great Britain and Ireland, and two consignments of trout and one of salmon ova were successfully sent to New Zealand.

1881, to supersede the Trentdale Fishery near Keswick, Cumberland. It is situ

The Solway Fishery, belonging to Mr Joseph J. Armistead, was established in ated near the Solway in Kirkcudbrightshire. Various kinds of trout and chart, salmon and sea-trout, grayling, and other freshwater fish are bred. The hatchinghouse is fitted to hatch about a million ova. Small and large quantities of ova are supplied to applicants for purposes of stocking or for experiments in fish culture.

The Stormontfield Ponds were established in 1853 by proprietors of Tay fisheries. They are situated about 5 miles above Perth on the Tay and occupy about 2 acres of ground. The Stormontfield experiments above referred to were carried out at these ponds under the direction of Mr Robert Buist. The establishment is now almost superseded by the Dupplin Hatchery, but is still used to some extent. The hatching-boxes, 360 in number, are in the open air, and the eggs are placed on gravel at the bottom of the boxes; a larger percentage of loss occurs with this system than when glass grilles are used. Two of the ponds at Stormontfield are stocked with parr from the Dupplin Hatchery, about 20,000 being placed in them in 1884; the parr are fed with ground liver, and are liberated in the river and its tributaries when two years old.

The Dupplin Hatchery was instituted in 1882 by the Tay district_board_at Newmill, Dupplin Castle, on the river Earn, a tributary of the Tay. The hatching-house is supplied with spring water, and contains about 300,000 ova. The glass grille system is adopted here, and the fry are liberated in tho Tay and its tributaries when about forty days old.

There is a hatchery for Loch Leven trout erected in 1883 by the Loch Leven Angling Association, situated about 800 yards from the luch, beside a small stream. In the season of 1884-85 about 220,000 eggs were laid down. The fry are turned into the feeders of the loch five or six weeks after hatching. Before the erection of this hatchery Loch Leven was several times stocked with fry from the Howletoun Fishery. The great effect of stocking on the produce of Loch Leven is shown by the following figures:-in 1884 over 15,000 trout were taken in the loch during the season from April to September; during the preceding ten years the lake had been suppled with some thousands of fry in five several seasons; previous to 1874 no attempt at stocking had been made, and in that year the total catch was about 5000.

In May 1884 the Linlithgow Palace Loch Hatchery was opened by its proprietor, Mr A. G. Anderson, fish merchant, Edinburgh, who holds a lease of the loch tor angling purposes from the crown. The hatchery is intended chiefly to stock the loch, and is capable of containing about 600,000 ova. Experiments on the cultivation of Salmo salar, var. sebago, from America, are also to be made here.

A private hatchery belonging to the marquis of Ailsa, capable of hatching about 250,000 ova, is situated at Culzean in Ayrshire. Salmon ova are obtained from the rivers Doon, Stinchar, and Minnock, and the fry turned again into those rivers when about six weeks old. Charr, S. fontinalis, and Loch Leven trout are also hatched to stock the hill lochs of the estate of Culzean. According to Mr Young the number of salmon in the Doon has been considerably increased by the artificial stocking from this establishment.

Another private hatchery, with a capacity of 50,000, is maintained on the Lochbuy estate, Isle of Mull, for the purpose of stocking the rivers and lakes on the property.

The Aberdeen Hatchery was established in Aberdeen by the district boards of the rivers Dee and Don. From 15,000 to 20,000 fry are hatched here every year and are conveyed 10 to 40 miles up the rivers Dee and Don and then liberated. Various proprietors in Scotland have at various times erected small hatchinghouses on the rivers of their estates for the purpose of stocking, but these have not been inaintained. The above-mentioned are the only salmon-rearing establishments of any importance at present in operation in Scotland.

Salmon Discase.

During the last few years salmon in a great many rivers have been observed to be suffering from an epidemic cutaneous disease from which large numbers have died. So far as is known this disease in its epidemic form is quite a now phenomenon; there can be little doubt that it must have occurred as a sporadic affection in former times, but it seems on the other hand probable that such mortality among salmon as has taken place in some recent seasons must have attracted attention if it occurred, even when accurate observation was rare. The disease was first noticed in 1877 in the Esk and the Nith, flowing into the Solway Firth, and since then it has destroyed very large numbers of salmon in almost every river in Britain. The disease consists in ulcerations of the skin, which begin at one or several spots on the head and body, and ultimately extend to the whole surface of the fish. The diseased parts of the skin are found when examined to be covered with a fungoid growth, with the mycelium of a fungus consisting of plaited hypha which extend into and ramify through the tissue of the derma and epidermis, causing the cells to die, until the superficial tissues decay and slough off, and inflammation and bleeding are produced in the deeper and surrounding parts. It is certain that the injury to the skin and flesh of the salmon is caused by the fungus. If a section of the edge of an affected spot be mado, and examined microscopically, the cells are seen to be perfectly normal and healthy beyond the region to which the hyphae extend, and the growing points of the hyphae are seen to be penetrating between and distorting these uninjured cells. It is evident therefore that the morbid alteration of the tissues follows the attack of the

hyphae and does not precede it. The external superficial part of the mycelium covering a diseased spot of the skin bears the fructification of the fungus. This consists of zoosporangia, which are the enlarged blind terminal parts of certain of the hypha,

prise cereals (wheat, barley, oats, maize, rye), tobacco, wool, cotton, poppy seed, opium, cocoons, prunes, and timber. In 1884 the industrial establishments were steam flour-mills, a cottonspinning factory (employing 500 hands and sending its goods to Constantinople, Smyrna, and Beyrout), a distillery, several large soap-works, a nail factory, an iron-bedstead factory, and a number of brick and tile works.

In Salonica the several nationalities have schools of their own: the Greeks, for example, havo a normal school, a gymnasium, and nine other schools (one for girls); and even the Bulgarians, though their members are comparatively small, have two normal schools. The Jewish community (about 50,000) is of Spanish origin, and still preserves its Judæo-Spanish written in Hebrew characters. Besides their own schools they have the advantage of a large school Fupported by the Jewish Mission of the Established Church of Scotland (instituted about 1860). The total population of Salonica was estimated by Tozer about 1865 as 60,000. It has since increased probably to 90,000 or 100,000. The railway opened to Kiuprili (136 miles) in 1873 is now extended 75 miles to Mitrovitza.

History. The older name of Thessalonica was Therma (in allusion to the hot-springs of the neighbourhood). It was a military and commercial station on a main line of communication between Rome and the East, and had reached its zenith before the seat of empire was transferred to Constantinople. It became a Roman colonia in the middle of the 3d century, and in the later defence of the ancient civilization against the barbarian inroads it played a considerable part. In 390 Thessalonica was the scene of the dreadful massacre perpetrated by command of Theodosius. Constantine repaired the port, and probably enriched the town with some of its buildings. During the iconoclastic reigns of terror it stood on the defensive, and succeeded in saving the artistic treasures of its churches: in the 9th century Joseph, one of its bishops, died in chains for his defence of image-worship. In the 7th century the Slavonic tribes strove to capture the city, but in vain even when it was thrown into confusion by a terrible earthquake which lasted several days. It was the attempt made to transfer the whole Bulgarian trade to Thessalonica that in the close of the 9th century caused the invasion of the empire by Simeon of Bulgaria. In 904 the Saracens from the Cyrenaica took the place by storm; the public buildings were grievously injured, and the inhabitants to the number of 22,900 were carried off and sold as slaves throughout the countries of the Mediterranean In 1185 the Normans of Sicily, having landed at Dyrrhachium and marched across country, took Thessalonica after a ten days' siege, and perpetrated endless barbarities, of which Eustathius, then bishop of the see, has left us an account. In 1204 Baldwin, conqueror of Constantinople, conferred the kingdom of Thessalonica on Boniface, marquis of Montferrat; but eighteen years later Theodore, despot of Epirus, one of the natural enemies of the new kingdom, took the city and had himself there crowned by the patriarch of Macedonian Bulgaria. On the death of Demetrius (who had been supported in his endeavour to recover his father's throne by Pope Honorius III.) the empty title of king of Salonica was adopted by several claimants. In 1266 the house of Burgundy received a grant of the titular kingdom from Baldwin II. when he was titular emperor, and it was sold by Eudes IV. to Philip of Tarentum, titular emperor of Remania in 1820. The Venetians, to whom the city was transferred by one of the Palæologi, were in power when Sultan Amurath appeared, and on the 1st of May 1430, in spite of the desperate resistance of the inhabitants, took the city, which had thrice previ ously been in the hands of the Turks. The body of St Demetrius, the patron saint, who from the time of his death under Maximian in the 4th century had exercised a marvellous influence on the popu lar imagination, was hacked to pieces, though even the Mohammedans attributed virtue to the famous oil from which the saint obtained the title of Myroblete. In 1876 the French and German consuls at Thessalonica wore massacred by the Turkish populace.

Besides Tafel's monograph, Dissertatio de Thessalonica (Berlin, 1839), see Holland's Travels (1815); Grisebach, Rumelien und Brussa, 1839; Bowen's Mount Athos, Thessaly, and Epirus (1852); Boeckh, CT G. vol. 11.; Texier and Pullan, Byzantine Architecture (1864); Tozer, Highlands of Turkey, 1869.

SALOP. See SHROPSHIRE.

SALSETTE, a large island to the north of Bombay, with an area of 241 square miles. It lies between 19° 2′ 30′′ and 19° 18′ 30" N. lat. and between 72° 51′ 30′′ and 73° 3' E. long.; it is connected with Bombay Island by bridge and causeway. Salsette is a beautiful, picturesque, and well-wooded tract, its surface being well diversified by hills and mountains, some of cor siderable elevation, while it is rich in rice fields. In various parts of the island are romantic views, embellished by the ruins of Portugueso churches, convents, and villas; its cave antiquities still form a subject of interest.

At the census of 1881 Salsette had a population of 108,149 (males 58,540, females 49,609); Hindus numbered 74,736 and Mohammedans 7,036. The island was taken from the Portugueso by the Mahrattas in 1739, and from them the British captured it in 1774; it was formally annexed to the East India Company's dominions in 1782 by the treaty of Salbai.

As

SALT. Common salt, or simply salt, is the name given to the native and industrial forms of sodium chloride (NaCl). The consideration of this important substance naturally falls under two heads, relating respectively to sea salt or "bay" salt and "rock" salt or mineral salt. actually found, however, the one is probably derived from the other, most rock salt deposits bearing evidence of having been formed by the evaporation of lakes or seas at former (often remote) geological periods. This is seen from their stratified nature, with their interposed beds of clay, which could only have been deposited from solution. The crystals of selenite (hydrated calcium sulphate), moreover, which they contain can only have been formed in water and can never since have been subjected to any considerable amount of heat, otherwise their water of crystallization would have been driven off. The beds also of potassium and magnesium salts found at Stassfurt and other places, interposed bctween or overlying the rock salt deposits, are in just the position in which one would naturally expect to find them if deposited from salt water. Finally, the marine shells often occurring abundantly in the surrounding rocks of contemporary periods also testify to the former existence of large neighbouring masses of salt water.

Sea Salt.-Assuming a degree of concentration such that each gallon of sea water contains 0.2547 Ib. of salt, and allowing an average density of 2.24 for rock salt, it has been computed that the entire ocean if dried up would yield no less than 4,419,360 cubic miles of rock salt, or about fourteen and a half times the bulk of the entire continent of Europe above high-water mark, mountain masses and all. The proportion of sodium chloride in the water of the ocean, where it is mixed with small quantities of other salts, is on the average about 33.3 per 1000 parts, ranging from 29 per 1000 for the polar seas to 35.5 per 1000 or more at the equator. Enclosed seas, such as the Mediterranean, the Red Sea, the Black Sea, the Dead Sea, the Caspian, and others, are dependent of course for the proportion and quality of their saline matter on local circumstances. Forchhammer found the following quantities of solid matter in the water of various seas:

North Sea....
Cattegat and Sound...
Baltic..

Mediterranean.

Atlantic..

Black Sea........

82.80 grammes per litre.

Caribbean Sea .................................................... Of this sodium chloride constitutes about four-fifths. See SEA WATER.

In

At one time almost the whole of tne sait in commerce was produced from the evaporation of sea water, and indeed salt so made still forms a staple commodity in many countries possessing a seaboard, especially those where the climate is dry and the summer of long duration. Portugal a total of over 250,000 tons is annually made in the salt works of St Ubes (Setubal), Alcacer do Sal, Oporto, Aneyro, and Figueras. Spain, with the salt works of the Bay of Cadiz, the Balearic Islands, &c., makes 300,000 tons. Italy has salt works in Sicily, Naples, Tuscany, and Sardinia, producing 165,000 tons. In France, between the "marais salants du midi" and those on the Atlantic, 250,000 to 300,000 tons are annually produced, besides those of Corsica. The "Salzgärten" of Austria produce collectively from 70,000 to 100,000 tons annually at various places on the Adriatic (Sabioncello, Trieste, Piranc, Capo d'Istria, &c.). In England and Scotland the industry has of late