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On the present occasion he gave a brief summary of his examinations.

The greatest depth at which specimens have been obtained is 1750 fathoms. The soundings from this and less depths, up to 1000 fathoms, consist almost entirely of microscopic organisms, such as those made known by Bailey, Wallich, and others, and procured by similar expeditions.

The marvellous profusion of Foraminifera and other minute structures in the soundings shows that there is forming at the bottom of the Atlantic, wherever it descends below the level of a few hundred fathoms, a wide spread of calcareous deposits, which will eventually become converted into beds of limestone. While nearly all the particles of these deposits are the shells of dead Foraminifera and their impalpable débris, it is evident that the surface of the Atlantic bed is one vast sheet of the same organisms in a living state, whose office it is to clear the waters of the ocean of the mineral and organic impurities which are ever flowing into them.

Although perforating-shells are living at great depths, Prof. King does not think there are any grounds for apprehending that they would bore into a telegraph cable; and he is inclined to believe that there is little chance of its getting injured if laid down on foraminiferous bottoms, as in such places chemical and vital actions appear to be going on so rapidly and unceasingly, that a cable cannot but become covered up in the course of a few years with a considerable deposit of calcareous matter.

The expedition has been fortunate in bringing to light some interesting facts in microscopic life,—in making known some species of shells and other animals new to the British fauna,-and in extending our knowledge of the habitats of certain rare species. A fishing-bank which has been discovered, yielded to the dredge, at 100 fathoms, Leda pygmæa, Pisidium fulvum, Arca raridentata, Limatula subauriculata, Scissurella crispata, Crania norvegica, &c., besides Sponges, Starfishes, and Sea Urchins. Of fishes, a species of Rhombus, allied to the Whiff, and a species of Sebastes, allied to the Norwegian Haddock, were dredged on the shallower parts of the bank. Specimens of a Pipe-fish were captured on the surface, nearly 200 miles west of Galway: the fishes appear to be unrecorded as British species. The same prolific bank yielded an abundance of a large Hermit Crab, specimens of which were taken tenanting the rare shell, Buccinum ovum. At the depth of 340 fathoms the lead brought up orbulo-globigerinous mud, containing dead specimens of a Pecten, an Arca, and a Pectunculus, all of which appear not to be known as British; also specimens of Trochus millegranus. A perfectly fresh specimen of a new Cochlodesma was also brought up from the depth of 1000 fathoms, 100 miles west of Cape Clear.

Notes on Sphærularia Bombi. By JOHN LUBBOCK, F.R.S.

In the first number of the 'Natural History Review' (January 1861), the author has given an account of this curious entozoon, which was first described by Léon Dufour, and very appropriately named by him Sphærularia Bombi, the generic name being taken from the spherules" by which the body is covered, and the specific name indicating the victims which are attacked. It has also been observed by Siebold, who met with the young. At one end, in every single specimen, was attached a small nematoid-like worm, closely resembling a young Sphærularia in form and size, and which the author presumed to be the male. So small however was it, so diminutive in comparison with its gigantic mate, that it had escaped the notice both of Léon Dufour and of Von Siebold. It was always attached in the same manner, namely, at a point near the tail, but distant from it by about one-fifth of the whole length of the animal, and was affixed to the female body almost at one extremity and at the end opposite to the opening of the female generative orifice. The internal organs of Sphærularia were stated to consist only of a long, single ovary and a double row of large cells, which were attached at the two ends, but, with that exception, lay freely in the general cavity. No mouth or anus, no intestinal canal, muscles, nerves, or vessels, were found in this curious and abnormal

entozoon.

The author now confirms his previous statements. He has also examined a

number of Bees in winter, hoping to ascertain the mode of development. But though he has met with specimens in which the female portion was so little developed as to be even smaller than the male, still in every case the organic whole consisted already of these two parts.

The youngest females contained a quantity of brownish granules, which extended from one end of the body to the other. As the animal increased in size, these granules remained stationary, and became more and more compact, so as to form a sort of rod. When the ovary became distinguishable, it was found that this rod, which in the meantime appeared to have undergone little alteration, occupied the lower part or uterus, with its lower end close to the vulva. In the younger females the eggs I did not descend in the uterus as far as the "rod;" but in more mature specimens the eggs as they made their way towards the vulva passed along the side of it, without breaking it up or altering its position. If therefore, as seems probable, the "rod" is the seminal element, the impregnation of the eggs is thus simply and thoroughly secured.

The author also gives some account of the development of the spherules and of the large fat-cells.

He expresses his regret that he has not yet been able to trace out the whole development, but it has not been from any want of perseverance on his part. He has examined in the winter months more than one hundred Humble Bees. The young Sphærularias, however, are very difficult to find, not only on account of their minute size, but because in consistence, colour, and form they so closely resemble the nerves, muscular fibres, and other organs among which they live. He hopes, however, that future researches may be more successful.

On two Aquatic Hymenoptera. By JOHN LUBBOCK, F.R.S.

On one of the early days in August, I was looking for larvæ in some water from a pond near my house in Kent, when I was astonished to see a small hymenopterous insect, swimming in the water by means of its wings. This was a phenomenon so surprising that at first I could hardly believe my eyes. Of the very large number of Hymenoptera already described, about 3500 occur in Great Britain; yet not one aquatic species is as yet known; while out of the whole immense list of insects, not one is yet recorded as using its wings under water. Entomologists might fairly, therefore, require good evidence before they receive as true a statement so opposed to all previous experience. Not only, however, did further examination disclose a second species, belonging to a different genus (which, however, used its hind legs, and not its wings, in swimming), but I was fortunate enough to succeed in exhibiting to the Entomological Society and also to the British Association living specimens of this interesting little insect.

Moreover it is a very remarkable fact that it was again observed within a few days, and yet quite independently, by another entomologist, Mr. Duchess of Stepney, who found a single specimen. It is certainly a curious coincidence that, after remaining so long unnoticed, it should be found by two separate observers within a few days of the same time. Perhaps this may be, in part at least, accounted for by supposing that during this season it has been more common than usual. I forwarded some specimens to Mr. Walker, who at first considered them to belong to Polynema fuscipes, but on a more careful examination satisfied himself that they belonged to a different and hitherto undescribed species, which I propose to name

P. natans.

Although it did not carry any external air-bubbles down with it, still it was able to remain alive under water for about twelve hours. The family to which it belongs pass their early stages as parasites within other animals, and the perfect insect probably enters the water in search of a suitable victim in or on which she may lay her eggs. Nevertheless the essentially aquatic habits of the species are proved by the fact that the male goes under water as readily as the female.

Without the assistance of figures, it would be useless to attempt any description of the separate parts; but I may remark that if this insect had been extinct, however perfect its remains might have been, no entomologist would have doubted that, like its congeners, it was entirely an aërial insect.

The species may be characterized as follows:-Polynema natans, n. s.: male, black; female, black; legs, eight basal segments of antennæ, posterior part of thorax, and peduncle ferruginous.

The second new species is more peculiar, and must form a new genus. It occurred with the first, but was much rarer, only six specimens having been met with, all of which were females. Perhaps the males are not aquatic in their habits. In this case, however, it was the hind legs which were used for swimming, although they possessed no fringe or other apparent indication to adapt them to their new function.

On the Influence of Changes in the Conditions of Existence in Modifying Species and Varieties. By the Rev. W. N. MOLESWORTH, M.A., Rochdale. The author of this paper commenced by giving a brief sketch of the main features of Darwin's theory of the origin of species, in order that its salient points might be kept in view by the audience during the reading of the paper. He then proceeded to point out that the theory thus outlined was not a mere wanton attack on beliefs and feelings which every one was bound to respect, but was intended to supply a scientific desideratum; and that, whether proved or disproved, it was calculated to advance our knowledge of the sciences to which it related. He wished it, however, clearly to be understood that his approval was limited to the theory of the origin of species, and not to the conjectures respecting the origin of organic life which are put forward at the close of the book-conjectures which, he submitted, it was impossible either to prove or disprove, or even to adduce any facts bearing on them, and which therefore cannot lead to any scientific results.

After considering some objections which had been made against the Darwinian theory, the author of the paper proceeded as follows:

And how is it that, with all their differences, they all possess so many characters in common? How is it that the line of demarcation which separates them is often so faintly traced that we lose sight of it altogether? These are the questions which Mr. Darwin raises, and to which he has given an answer, which, whether true or false, is certainly highly ingenious and original, and supported by a large array of facts. Whether his theory is true or not is a matter on which I express no opinion; but that a necessity exists for a theory on the subject to which it relates is, I would submit, a matter that admits of no doubt.

There is another of Agassiz's objections that seems to me better founded than that with which I have just been dealing. He says, "The assertion of Darwin, which has crept into the title of his work, is that favoured races are preserved, while all his facts go to substantiate the assertion that favoured individuals have a better chance in the struggle for life than others." In this passage Agassiz seems to me to have pointed out the respect in which Darwin's theory is defective and stands in need of further elaboration. I contend that he has not paid sufficient attention to a very manifest and important principle, which has probably played as large a part in the origination of species and varieties as either the struggle for existence or natural selection. I mean the change which is continually going on in the conditions of existence, and which, by affecting a great number of individuals in the same manner, tend to produce similar modifications in all the beings who are surrounded by them. In employing the term "conditions of existence," I mean to imply the totality of the circumstances by which the organized being is surrounded-the air, the climate, the soil, the vegetation, and the animals which inhabit the same area, including those of its own species. All these are, if we look at the matter rightly, conditions of its existence, inasmuch as all of them exercise a more or less powerful influence on it, causing it to be other than it would be if they were absent or different from what they are. The thing to which I desire to draw particular attention is the change which is always going on in these conditions of existence, owing to their mutual actions and reactions. For instance, the very constitution of the atmosphere is to a certain extent altered by every organized being, as well as by the inorganic matter with which it is continually entering into new combinations. If any one should suppose that the changes thus produced must be quite inappreciable even though carried on through millions of generations, let him reflect for a moment on the enormous quantity of former constituents of the

atmospheric ocean which are now buried in the form of coal and other fossil remains, as well as that far greater mass of animal and vegetable excrement and of other organic matter which is mingled with the inorganic substance of the earth's crust, and is composed in a great measure of ingredients abstracted from the atmosphere. Look again at the changes produced in the conditions of the existence of each animal by all organized beings inhabiting the same area. Some devour it, others are devoured by it; some become more scarce, others more plentiful; some exercise a beneficial, others an injurious influence on it; but all are in some way changing its conditions of existence, and all are being in their turn changed, as Mr. Darwin has so ably pointed out, by the struggle for existence and the process of natural selection. Again, all of them extract from the soil, directly or indirectly, some of its nutritious constituents, and return them to it in different forms, in different places, and under different chemical combinations. Add to all these other causes of change the action of the being itself in altering its own conditions of existence, and it will at once be evident that, in the course of such long periods of time as we have referred to, striking and marked changes must be produced in the conditions of existence of almost every species.

Hence it follows that if we suppose a group of beings to be at one period of their history in harmony with the conditions of their existence, they must at all subsequent periods be more and more out of harmony with it; and that, on the supposition of the invariability of the species, this discrepancy between the species and its environment must at length become so great that its extinction must become inevitable. It necessarily follows from this, that there must be on the part of the species a constant instinctive, though perhaps unconscious, effort to restore the lost equilibrium, to get rid of the sufferings which will arise from the want of it, and to place itself once more in harmony with its conditions of existence; and the greater the change in the conditions, the more strenuous will this effort be. Some one once remarked to Coleridge, "All things find their level." "No," replied that great man, "all things are finding their level like water in a storm." This saying appears to me to describe, with the happiness of genius, the nature of the incessant movement that is always going on in all parts of the world, and amongst almost all its animal and vegetable inhabitants. All are unconsciously striving to keep themselves in harmony with a medium which is continually changing.

In order, then, that they may not be utterly distanced by the ever-changing conditions of their existence so as in time to become extinct, they must possess a capacity for variation in the direction of those changes which is absolutely illimitable, provided only that sufficient time be allowed for its development. That they do possess such a capacity to a certain extent has been triumphantly demonstrated by Darwin. The real question is, Are there any, and, if so, what, limits to this capacity of variation in the direction of actual or possible changes in the conditions of existence? Now, in reference to this question, it seems to me that Mr. Darwin has not sufficiently distinguished between a capacity for variation and a tendency to vary, which, I would submit, are two very different things. I would respectfully contend that the capacity for variation is in the being; but the tendency to vary arises out of the changes which take place in the conditions of existence, and in the efforts unconsciously made by the being to overtake those changes. When, therefore, a species of animals inhabit the same area, they will, generally speaking, be exposed to nearly the same changes in the conditions of their existence. This will almost necessarily lead to similar variations manifesting themselves in the same individuals at the same time, because they will all be exposed to the same changes, and variations thus produced are much more likely to be strengthened and perpetuated than varieties arising from temporary causes, or such as affect individuals only. Mr. Darwin says, "When a variation is of the slightest use to a being, we cannot tell how much of it to attribute to the accumulative action of natural selection, and how much to the conditions of life;" and a little further on, "Such considerations as these incline me to lay very little weight on the direct action of the conditions of life. Indirectly, as already remarked, they seem to play an important part in affecting the reproductive system; and in thus inducing variability and natural selection, will then accumulate all profitable variations, however slight, until they become plainly developed and appreciable by us."

Now in these passages, and in every other part of his work in which he touches on the subject, Mr. Darwin appears to me to overlook, or at least not to make sufficient allowance for, the progressive changes which are always taking place in the conditions of existence of almost every living creature, although his book teems with proofs of it. But there is another oversight running through the work, and strongly exhibited in the passages just cited. Mr. Darwin speaks of natural selection as accumulating profitable variations, whereas it is quite evident that, at utmost, it can only repeat them. Natural selection acts, as Mr. Darwin shows, by preserving the serviceable variations, and discarding the unserviceable or injurious; but as it does not produce them, so neither of itself can it strengthen them: that, I maintain, is done by the conditions of existence acting on the variability of the animals which are placed among them. Mr. Darwin elsewhere writes:-"Seedlings from the same fruit, and young from the same litter, sometimes considerably differ from each other, though both the young and the parents, as Müller has remarked, have apparently been exposed to exactly the same conditions of life; and this shows how unimportant the direct effects of the conditions of life are in comparison with the laws of reproduction and of growth and of inheritance; for had the conditions been direct, if any of the young had varied, probably all would have varied in the same manner." I deny this probability. If Mr. Darwin has certainly established anything, it is this, that animals do possess a capacity for variation in almost every direction. But it is equally certain that this capacity for variation differs very much in different individuals, so that the same influences do not produce the same effects, though they tend to do so. And therefore even if we assume (which I am not prepared to admit) that the conditions of life are the same for seedlings of the same fruit, and young of the same litter during the period of gestation, still it would not follow that they were either absolutely or comparatively unimportant, or that the variations which showed themselves were not due to them. In a word, I contend that the capacity for variation is in the animal, but that it depends in a great measure for its development on that assemblage of circumstances which we denominate the conditions of its existence; and the changes, which in the greater part of animals are slowly taking place in those conditions, impress on the variations a certain definite direction, while natural selection tends to the preservation of the most favourable of the variations thus produced. At the same time I am by no means prepared to deny the influence which Mr. Darwin attributes to the laws of reproduction and growth: all I maintain is that he underrates the influence of the conditions of life, and overlooks that of the changes which are slowly but continually taking place in them, at least for most organized beings; and he further employs language which seems to imply that natural selection has something to do with the production of favourable varieties, when all his arguments go to prove that it tends only to the preservation of those which have been produced by other causes. I maintain therefore that two classes of inquiries ought simultaneously to be carried on-one into the variability of organized beings, and another into the variations of the conditions of their existence.

After illustrating these views at some length, the author of the paper concluded as follows:

This is not the place for entering on the theological aspects of the question. Indeed, I am forbidden, I believe, by the rules of the Association to do so. So far from regretting this prohibition, I cordially approve it, regarding it not merely as a regulation of wise expediency, but as the embodiment of a sound principle. I maintain that the intrusion of Scriptural arguments into scientific investigations is as theologically erroneous as it is scientifically mischievous. Let us push our investigations of the Creator's works as far as we can in every direction, without the slightest fear that scientific truth can ever clash with moral and religious truth; and let us apply to the theory before us what Galileo said of his when exposed to objections similar in principle to those which had been urged against Mr. Darwin's, "Quin ipsa philosophia talibus e disputationibus non nisi beneficium recepit. Nam si vera proponit homo ingeniosus veritatisque amans nova ad eam accessio fiet; sin falsa, refutatione eorum priores tanto magis stabilientur."

1862.

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