934 SUMMARY OF CURRENT RESEARCHES RELATING TO 



become free by the dissolution of the membrane of the mother-cell, 

 fall to the ground, and germinate when brought into a suitable 

 nutrient fluid. After from one to two hours the spores swell to 

 twice their volume, lose their refrangibility, and put out the young 

 rod laterally, i. e. at right angles to the longer axis of the spore. 

 This rod then lengthens rapidly, frees itself from the membrane of 

 the spore, and swims free, the membrane showing evident thickenings 

 at both ends. 



The bacterium of cattle-distemper, B. antliracis, exhibits several 

 variations from this in its development, and especially in the mode of 

 germination. Under similar conditions to those of B. subtilis the 

 spores of B. antliracis lose their refrangibility much more rapidly, 

 and in the course of 15 or 20 minutes, swell up to several times their 

 orio-inal volume. They then present a close resemblance in appear- 

 ance to the young rods of B. subtilis ; but they germinate only after 

 from one to two hours, and then the young rod always breaks through 

 the spore-membrane at both ends, growing in the direction of its 

 longer axis, then growing rapidly and increasing by division. After 

 attaining a certain length it throws off the membrane, which is a thin 

 delicate envelope of equal thickness throughout. 



Although regarding these two forms as distinct species, Praz- 

 mowski agrees with Buchner and Pasteur in stating that, under ' 

 certain conditions of culture, the bacteria of cattle-distemper may 

 produce non-pathogenous forms agreeing with the pathogenous in 

 their morphological characters and the history of their development. 

 Bacterioidomonas sporifera.* — Under this name J. Kiinstler 

 describes a parasite inhabiting the caecum of Cavia, and possessing 

 characters that connect it with the Schizomycetes as well as with the 

 animal kingdom. In outward appearance it presents an oval form 

 slightly flattened from head to tail, and when fully developed attains 

 a length of about 24 ju,. It progresses tolerably rapidly and with a 

 rectilinear movement by means of a long flagellum implanted at the 

 anterior end of the body. When once the difficulty of staining it 

 with reagents is overcome its structure under a high power is seen to 

 consist of a peripheral layer forming an enveloping membrane of 

 nitrogenous nature, and a pale protoplasmic interior presenting a 

 finely stippled aspect. In the centre is a rounded corpuscle of finely 

 stippled protoplasm, destitute of nucleolus, and presenting none of 

 the characters which render certain nuclei so complex. This nucleus 

 is not always single, individuals frequently being found which have 

 one at each extremity. 



Eeproduction takes place by the development of spores within the 

 interior of the body, whence they are liberated through the rending 

 of the body-wall. A flagellum subsequently forms, and they would 

 appear to be capable of increase by division. Ordinarily they twist 

 themselves little by little into a tendril-like form, when they resemble 

 a thick Spirillum. 



The nutrition of Bacterioidomonas takes place by imbibition ; no 



* Joura. de Microgr., viii. (1884) pp. 376-80 (1 pi.). 



