mission report that in the case of the 19 trial dogs, of six which were bitten, rabies occurred in three, of seven which were inoculated in a vein it occurred in five, and of five which were inoculated by trephining it occurred in all, while not a single sign of rabies has shown itself in any of the 19 vaccinated dogs.

During the course of the inquiry one of the protected dogs died July 13 from a sanguineous diarrhoea, which first declared itself in the early days of that month. In order to determine whether rabies had any share in its death, three rabbits and one guinea-pig were at once inoculated with its bulb by trephining. All of these

four animals are still in the best of health, which is a certain proof that the dog did not die of rabies, but of a common disease.-Med. Times, London, August 23.

MICRO-ORGANISMS AND DISEASE. BY E. KLEIN, M.D., F.R.S.

(Continued from p. 258.)

THE bacilli in the tuberculous deposits of cattle are always contained in the cells; the larger the cell the more numerous the bacilli. This fact comes out very strikingly in thin and well-stained sections. Around many of the smaller and larger clumps of bacilli the celloutline is still recognizable, and when the cell disintegrates, as it does sooner or later, the bacilli become free in groups; in this respect there exists a remarkable similarity between

tissue of lupus. But the bacilli occurring in the lupus-tissue, as far as I am able to see, are morphologically different from the tuberclebacilli. In a preparation made of the juice of lupus-tissue, large transparent cells with several nuclei are found, in the cell-substance of which are noticed groups of thickish short bacilli, thicker and shorter than tubercle-bacilli. These bacilli are either placed singly or in chains of two.

The so-called Bacillus of Cholera.-In the reports from India by Dr. Koch, as the head of the German Commission sent to investigate the recent outbreak of cholera in Egypt, we notice that, like the French Commission, they failed to communicate the disease to animals; that the German Commission failed to discover any specific organism in the blood of patients suffering from cholera; that the intestines contained in their cavity and wall numerous peculiar "comma

From the artificial cultivations of these comma-shaped bacilli, Koch learned that it is necessary that the nourishing material should have an alkaline reaction, and that the bacilli are easily killed by drying. Koch found these comma-shaped bacilli in linen soiled with the cholera dejecta, also in the water of a tank that had produced cholera in several people who had partaken of it. As soon as the bacilli disappeared in this water cholera cases ceased. Mr. A. Lingard has placed at my disposal sections through the human intestine from cases of dysentery; there are seen in the superficial parts of the necrosed mucous membrane large numbers of putrefactive bacilli. In some cases, however, in the depth of the tissue there are found, amongst the extravasated blood-corpuscles, numbers of very fine, long, straight, or more commonly curved, bacilli and bacillus-filaments; some are distinctly made up of a chain of long bacilli. They stain well and conspicuously in methylblue. [See MED. ABS., Sept., 1884.]

VIBRIONES are characterised by being rodshaped, but not straight; they are more or less wavy; and they are motile. (a) Vibrio rugula consists of rods of about 0'008 to o'016

FIG. 4.-VIBRIO RUGULA (AFTER COHN). mm. in length, and are curved either like a C or like an S. They are single, or form chains of two. Their protoplasm is always slightly granular. They are found in putrefying organic substances, and often form continuous masses, the individuals interlacing in all directions. (b) Vibrio serpens. This is also a septic organism, much thinner and longer than the previous one, more wavy, as a rule, curved into a single or double wave. The length

ISOLATED (AFTER COHN). IN SWARMS (AFTER COHN). SPIRILLA are filaments of a spiral shape, motile, and owing to their shape follow a spiral course when moving. They are probably capable of forming minute bright spores. Septic spirilla are found in all kinds of putrefying organic substances, and are of three

I.

FIG. 7.-SPIRILLUM TENUE, (1) SINGLY AND (2) IN SWARMS (AFTER COHN).

kinds. (a) Spirillum tenue is much finer and more wavy than vibrio serpens, the turns being closer together and spiral. Its length varies between 0'002 and o'005 mm. ; it often forms continuous felted masses; it is motile. Occasionally the spirilla grow to a great length -two, three, and more of them forming a chain; the individual spirilla are not arranged in a linear series, but folded into a zigzag. This form, which in reality is not a special kind of spirillum, is called by Cohn spirochata plicatilis. The spirillum found in the tartar of the teeth is of this form, spirochata denticola. But there exist all intermediate forms between a single spirillum tenue and a spirochata, In stained specimens the construction of the spirochæta from several spirilla tenua is very distinct. (b) Spirillum undula is much thicker and shorter than the former; there are all forms between such as are only half a turn to such as are of a whole turn of a spiral. It is motile and forms chains of two or more elements, occurring also in continuous masses,

and physiologically by their action on various fluids (see below).

The cells multiply in suitable media by gemmation, a minute knob-like projection appearing at one side of the cell, and enlarging till it reaches nearly the size of the original or mother-cell. It finally becomes altogether constricted off from this latter, or having reached its full size remains fixed to the mothercell, and each cell again producing by gemmation a new cell. In this way aggregations of four, six, eight, or more cells are formed, which may be arranged either as a chain when the production proceeds in a linear manner, or, if the gemmation takes place laterally as a group.

Under varying conditions of growth, e.g. on transplanting ordinary yeast growing on sugarcontaining fluids on to potato, but sometimes also in the same nutritive fluid, it is observed that some of the yeast cells enlarge twice, thrice, and more times; they then form in their interior two, three, or more small cells by endogenous formation; these new cells are regarded as spores-the mother-cell being an

(c) Saccharomyces pastorianus is of various kinds (Hansen): in some the cells are about o'002 to 0'005 mm. in diameter, in others larger. Some form ascospores, others do not. Most of them can be found in wine-fermentation and in cider-fermentation, but only after the first alcoholic fermentation is completed. They are very common in the air. I have sown a saccharomyces, which was contained in ordinary water, on a solid nourishing media (gelatine, and gelatine and broth). It grew up copiously and formed groups of a distinct pink colour. When growing in the depth of the nourishing medium it grew as a colourless torula, no ascospores were formed, multiplication taking place by gemmation only.

(d) Saccharomyces mycoderma (Mycoderma vini). This yeast is found forming the scum or pellicle on the surface of wine, beer, and fermented cabbage (Sauerkraut); its cells are oval, about o'006 mm. long and o'002 broad. It forms chains; the ascospores are two or three times larger. It has nothing to do with the alcoholic fermentation, and is not to be confounded with mycoderma aceti, which is a

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O

FIG. 12.-TORULA OR SACCHAROMYCES.

In the lower part of the figure an ascospore and four isolated spores (after Rees) are shown. Magnifying power about 575.

FIG. 13.-SACCHAROMYCES MYCODERMA, OR OIDIUM ALBICANS X575..

the membrane of the mother-cell. On sowing these new cells into sugar-containing fluids they multiply by the process of gemmation.

Classifying them according to physiological function there are various species of torula or saccharomyces. They all have the power to split up sugar into alcohol and carbonic acid, but this power is not possessed by all to the same degree.

(a) Saccharomyces cerevisia (Torula cerevisia). This is the ordinary yeast used in the production of beer. The individual full-grown cells vary in diameter from o'008 to o'or mm.; they form beautiful long chains. They produce ascospores.

(b) Saccharomyces vini is very common in the air, and produces alcoholic fermentation of grape-juice; it is therefore the proper yeast of wine-production. Its cells are elliptical, slightly smaller than the former; it forms ascospores.

material.

d. Branched mycelium. fa. Torula stage. fB. Mycelial stage. (After Grawitz.)

bacterium and the efficient cause of acid fermentation in wine and beer.

The saccharomyces mycoderma does not grow well in the depth of liquids, but when sown into a liquid of acid reaction and containing but little sugar, Cienkowsky saw the cells elongating into cylindrical elements; each of which by gemmation produced a new cell which also elongated, and so on till a linear series of cylindrical cells was formed, separated from one another only by a thin septum; a mass of filaments very much resembling a mycelium was thus formed. The cylindrical cells give origin by gemmation to spherical and elliptical torula-cells.

Such a growth, in which the torula-cells are capable of forming a sort of mycelium, was