Minute

surface of the tongue, I cultivated it upon a warm stage. portions of fur from different tongues were placed in a drop of aqueous humour, and kept at a temperature of 30° to 33° C. Free growth and development took place, but instead of the single fungus I had expected several fungi were found. Only two forms, however, were present in every instance, namely, Micrococcus and Bacillus, and, from a comparison of the natural fur with results obtained by artificial cultivation, I think there can be little doubt that the fur consists chiefly or essentially of these two fungi.

Micrococcus existed in every case examined, small spherical bodies generally in pairs or groups of four, but often forming chains. Upon the warm stage rapid multiplication took place with the production of pairs, fours, long and short chains often twisted and looped, and small and large colonies. When these colonies reached a large size (which happened in the course of a few hours) they presented a granular appearance and assumed a yellow or brownish-yellow colour, and all movement ceased in them.* The development of Micrococcus occurred abundantly and rapidly in all the experiments made with the exception of one, in which so rapid a formation of Bacterium termo took place, that in the course of a few hours the whole of the fluid was clouded and obscured by its presence. Usually the development of other fungi did not interfere with that of Micrococcus. Comparing the masses or colonies produced by cultivation with the granular masses of which the fur chiefly consists, the chief constituent of each appears to be the Micrococcus sphere. The natural colonies are, of course, not often so pure as those produced artificially, but still not uncommonly these natural colonies present the same regularity of structure as the colonies figured in sketch 5.

The other form, Bacillus, was also present in every case examined, but unfortunately development seldom or never occurred, being apparently prevented by the presence of other fungi. It consisted of slender rods, having a well-marked double contour and a light interior. Their length varied much, but was always many times their breadth. There were no defined contents within the rods, except in some of the longer and broader of them, which contained highly refractive spherical bodies which appeared to be spores. The shorter rods moved actively about the field of the microscope, and even some of the longer rods (looking when magnified 450 times from inch to 1 inch long) moved slowly from place to place. The rods were generally straight, but some of the longer ones were curved or bent. They often formed short chains or occurred in pairs, but did not form colonies, although they sometimes occurred in great number and of large size in the Micrococcus colonies. They showed very little

* I never observed any lengthening into rods, or the development of any other form from these Micrococci.

change in appearance for many hours, sometimes for two or more days, after which they usually became granular and degenerated. These bodies are apparently identical with the Leptothrix buccalis of Robin. But I think they would be more rightly called Bacillus subtilis. Their length, their slender form, the conditions in which they occur, and the fact of their non-development in the presence of other fungi point to this conclusion. I made many attempts to separate them in order to produce the fungus in a purer form by cultivation, but did not succeed in doing so. Although this fungus did not develop under artificial conditions in the presence of Micrococcus and other fungi it is highly, probable that its development takes place freely upon the surface of the tongue. Its habitual presence there, generally in tolerable abundance, and the occurrence of spore-bearing filaments may be adduced as evidence in favour of this view.

Besides these fungi Bacterium termo existed in some of the furs examined, and twice developed with such rapidity that the whole of the fluid was crowded with these organisms to the exclusion of every other form. Pairs, chains, and colonies were formed.

Sarcina ventriculi was frequently present and generally developed quickly. It usually occurred in pairs or fours, and was easily recognisable by its large size, compared with the other organisms present, by the square or oblong form of its nuclei, by their faint yellow or red tint, and by the area of protoplasm surrounding the nuclei. The groups of two or four moved slowly about the field of the microscope, but the large masses which were formed remained quite motionless. The masses attained so large a size as seriously to interfere with the growth of some of the other organisms, and when large showed a decided yellow, or brownish-yellow colour.

In two or three of the specimens there occurred rapid and very abundant development of a form of Spirillum, which appeared from the double twist which it exhibited, and from its extreme tenuity, to be Spirochaeta plicatilis. Its growth took place from exceedingly small portions of the organism, and continued only at one end, which was in constant motion, whilst the other end remained stationary; and as the growth progressed, large masses were formed which soon became so dense that it was impossible to discern the nature of the organism of which they were composed. This Spirochaeta did not

occur in most of the specimens examined.

A larger form of Spirillum was also occasionally present, but was not seen in the act of developing.

Although I believe the fur consists chiefly of Micrococcus and Bacillus subtilis, I think it is probable from the results obtained in the experiments upon which the foregoing observations are founded, that the development of these other forms (Bacterium termo, Sarcina ventri

culi, Spirochaeta plicatilis) may often add considerably to its bulk, and may, perhaps, modify its characters under certain conditions.

The slime which exists around and between the teeth is composed of the same constituents as the fur on the tongue; all the organisms which are found in the one are found also in the other. Bacillus subtilis exists, however, in greater quantity in this tooth-slime than in the fur, and the rods and filaments are usually much longer in the toothslime, probably because they are not subjected to so much disturbance.

In conclusion I have to thank Dr. Burdon Sanderson and Dr. Lauder Brunton, for valuable suggestions, and for the kindly interest they have shown in this work.

A List of the principal Works relating to the Nature and Character of Tongue Fur.

1831. Piorry.

1845. Remak.

"Du Procédé Opératoire." Paris, 1831.

Diagnostische und Pathologische Untersuchungen." Berlin, 1845, s. 221.

1849. Pfeufer. "Der Mundhöhlenkatarrh." Henle u. Pfeufer. Ztchft. f. Rat.

1853. Robin. 1861.

Med., Bd. 7, 1849, s. 180.

Untersuchungen über der Zungenbeleg."
Jahrschft., 1850, Bd. 28, s. 44.

"Végétaux Parasites." Paris, 1853, p. 345.

66

Prager Viertel

Neidhardt. Mittheilungen über die Veränderungen der Zunge in Krankheiten." Arch. d. Wissensch. Heilkunde, Bd. v, 1861, s. 294.

Hyde Salter. Todd's "Cyclopædia of Anatomy and Physiology." Art. "Tongue." Vol. iv, pt. 2, p. 1161.

1866. Hallier. "Die Pflanzlichen Parasiten." Leipsig, 1866.

1867. Kölliker.

"Handbuch der Gewebelehre." 5th Auflage. 1867. Ss. 348

349.

1873. Fairlie Clarke. "Diseases of the Tongue." London, 1873, p. 93. Billroth. "Coccobacteria septica." Berlin, 1874, s. 94.

1874.

Robin.

"Leçons sur les Humeurs." Paris, 1874, p. 550.

1877. Koch. "Untersuchungen über Bacterien." Cohn's Beiträge zur Biologie der Pflanzen, Bd. II, Hft. 3, s. 399.

II. "Note on the Supplementary Forces concerned in the Abdominal Circulation in Man." By J. BRAXTON HICKS, M.D., F.R.S. Received March 26, 1879.

During the ordinary inspiratory effort, the descent of the diaphragm, most noticeable in the male, necessarily produces pressure on the abdominal viscera in contact with its lower surface; these in their turn press down the intestines, which, acting as fluid enclosed in closed. elastic sacs, press equally in all directions. Thus during each descent the abdominal walls are projected forwards, as may be readily seen by adapting an instrument similar to a cardiograph resting on three feet,