298 SUMMARY OF CURRENT RESEARCHES RELATING TO 



tains the absolute specific distinctness of Bacillus anthracis and 

 B. snbtilis. The spores of the two bacteria disiiLiy a difference in 

 the structure of their spore-membranes, and a corresponding different 

 mode of germination. In B. anthracis the membrane is of uniform 

 thickness throughout, and, on germinating, bursts at one end of its 

 longitudinal axis. In B. suhtllis it is thickened at both ends of the 

 elliptical spore, and germination takes place in a direction at right- 

 angles to its longer axis. The morphological characteristics of B. 

 anthracis, and also, in the main, its physiological properties, are 

 perpetuated even when it has lost its pathological properties by 

 artificial cultivation. In other respects it only changes its physio- 

 logical characters by passing over more readily into the swarming 

 condition, and, in consequence, collecting towards the end of its 

 growth, especially on the surface of the nutrient fluid, where it forms 

 thickish dirty wliite pellicles after the manner of B. suUilis ; but the 

 two still present points of difference. 



Prazmowski's investigations indicate only that, under certain 

 conditions of artificial culture, B. anthracis may lose its capacity of 

 multiplying in the animal organism, and producing the cattle- disease. 

 He has observed also in this species a new and peculiar resting con- 

 dition. The rods exude a thick gelatinous membrane, which soon 

 becomes hard, and then forms a kind of tough and firm envelope 

 round the delicate rod. Under favourable conditions an ordinary rod 

 is then developed from this resting form by the envelope becoming 

 ruptured at a certain point, and the young rod then growing out from 

 this spot as in the germination of the spores. 



Diagnostic Value of Tubercular Bacilli.* — Friedrich Miiller 

 epitomises the facts at present known with regard to the value of the 

 characters presented by the different bacilli which accompany the 

 various forms of tubercular disease. To these diagnostic characters 

 he attaches great value. The micro-organisms characteristic of 

 tuberculosis and of lepra present great similarity in their forms, 

 mode of formation of the spores, and arrangement iu groups ; in the 

 latter case, however, they are present in enormous quantities, while 

 in the former their number is comparatively small. 



Odour and Poisonous Effects of the Fermentation produced by 

 the Comma Bacillus. f — W. Nicati and Eietsch find that pure culti- 

 vations of the " comma " Bacillus have a characteristic ethereal odour, 

 quite different from that of putrid substances. This is the odour of 

 the intestinal matter of cholera patients in the early stages, especially 

 if it is kept in a moist atmosphere at 25''-35° for 24 hours. If pure 

 cultivations of this Bacillus in Koch's gelatin or in beef-tea, after at 

 least eight days, are freed from Bacilli by being passed through a 

 Pasteur's filter, and the clear liquid is injected into the circulatory 

 system of dogs, choleraic symptoms of varying degrees of violence 

 are produced. The same liquid when injected under the skin has 

 no effect. Recent cultivations are also absolutely inactive. 



* Vcrli. riiys.-mcd. ncsoU. Wiirzburg, xviii. (1884) jip. 1-8. 

 t Comptes Rendug, xcix. (1881) pP- ^'^^-2. 



