496 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Lankester as Bacterium rubescens, show many jioints of analogy with 

 those of chlorophyll. Milk appears to be unfitted for the growth of 

 the bacterium. In conclusion, the author argues at some length in 

 favovu- of the cellular nature of bacteria. 



Bacillus of Contagious MoUuscum.* — M. Domenico, who has 

 previously upheld the contagious character of this disease, has 

 undertaken experiments of artificial culture to determine the exact 

 nature of the dififerent structures which have been shown by Dr. A. 

 Angelucci to accompany it. The molluscous nodules were kept 

 either in distilled water, or in the moist chamber ; the vessels were 

 hermetically sealed, and kept at a temperature of 20°-30° C. 



Microscopical examination of such specimens (1) after three hours, 

 showed that the granidss had multiplied and grown larger, and had 

 altered in appearance from that of micrococci to that of sporidia, being 

 very mobile, refringent, and varying in shape ; they now form aggre- 

 gations around the yellow halls of the molluscous capsule, among the 

 ejiithelial cells, and in the lining connective tissue ; (2) After six 

 hours' culture the sporidia have become fewer, and are in part 

 replaced by strings, flakes, or more compact masses of Bacilli, which 

 surround the yellow balls ; they exhibit lively forward or rotating 

 movements when warmed. In twelve hours the masses of sporidia have 

 entirely disappeared ; the Bacilli now occur in the capsule and 

 interstitial connective tissue ; some of them may be seen united in 

 pairs by an interposed sporidium, and bent at an angle ; others bear 

 a sporidium at one end. They exactly resemble figures of Bacillus 

 leprae, and B. malarioe. (3) In twenty-four hours the naked eye 

 can perceive a whitish zone surrounding the nodules, and threads 

 floating in the cultivating liquid ; both appearances are caused by 

 masses of Bacilli, and by zigzag bacillar filaments, among which 

 clusters of sporidia have again appeared. In two days the surface of 

 the liquid is covered with whitish masses of sporidia and bacillar 

 filaments, and hardly any separate Bacilli occur. Thus the "granules" 

 of this disease are not Micrococci of Cohn's classification, but are 

 sporidia of a more highly organized species, the Bacillus rnollusci. 



Fungus of Ringworm (Trichophyton tonsurans). f — Dr. G. Thin 

 writes that when hairs aftected with the Tricliopliyton tonsurans are 

 cultivated in cells, the development of the spores on the sides of the 

 hairs can, if it occurs, be observed in situ under the Microscope. 

 When the attempted cultivation takes place on the surface of a fluid 

 in a test-glass, it is also possible, after maceration in solutions of 

 potash, to decide whether the spores in the hairs have grown out from 

 the surface of the hair, and to distinguish between a growth of 

 adventitious fungi and the growth of the Trichophyton. 



An account is given of experiments made by the use of cells and 

 test-glasses, which were kept at a temperature of between 92° and 

 98^ F., but in a few instances at the ordinary room temperature. The 



* Atti Accad. Lincei, Transunti, v. (1880) pp. 77-9. 

 t Pruc. Rnyal Soc, xxxi. (1881) pp. 501-2. 



