MICROPHYTES FOUND IN THE BLOOD. 369 



merelj. Cultivation-experiments were, however, also under- 

 taken, and it was found that in the course of 3 to 4 hours the 

 development of these bodies could be observed under suitable 

 conditions. On careful examination each ' spore ' is seen to be 

 an oval-shaped body embedded in a translucent substance which 

 appears to surround the former in a ring-like fashion, but is 

 seen to be in reahty spherical, on being rolled over. This sub- 

 stance loses its spherical form and becomes elongated at one 

 end in the direction of the long axis of the contained ' spore.' 

 The latter remains at one end, and very soon the translucent 

 tube assumes a filamentous aspect and, contemporaneously, the 

 'spore' becomes less refringent, pale, and small, and possibly 

 breaks down into fragments, until it eventually disappears com- 

 pletely.^ Dr. Koch's figure (fig. 5), representing the various 

 stages of the supposed germination process, is reproduced. 





YiG. 5. Fig. 6. 



Fig. 5. — Bacillus anthracis : Germiuation of the spores (after Koch). 



X 650 diam. 

 Fig. 6. — Bacillus anthracis: Germination of the spores (after Cohn). 



X 1050 diam. 



This interpretation of what occurs is made particularly im- 

 portant from the fact that it has been resorted to very lately 

 by M. Pasteur to account for the circumstance that, although it 

 has been proved, beyond all reasonable doubt, that splenic fever, 

 together with blood-bacilli, may be induced by inoculation with 

 virus after the total destruction of the filament-bacillus which 

 the morbid material had contained, yet because the ' spores ' 

 remained (it would seem that they are considered nearly inde- 

 structible) the virus had retained its property — the ' spores ' in 

 fact being the virus. 



Professor Cohn favoured Dr. Koch with a sketch of the same 

 developmental process as seen under a higher power. This figure 

 is also reproduced for purposes of comparison. Koch suggests 

 that probably the ' spore ' consists of a strongly refractive sub- 

 stance, probably oil, which is enveloped by a thin layer of pro- 

 toplasm — the latter being the substance capable of germination, 

 and the former, perhaps, serving as nourishment during the 

 ' Loc. cit., p. 289. 



