400 



iMICRO-ORGANISMS AND DISEASE [chap. 



anything to do with its active principle. Now, the above 

 minute bacilli which I have described aho\c as occurring 

 abundantly in early phases in calf-lymph— in some instances 

 so abundant that the lymph looks like a culture of them — 

 are not cultivable in the ordinary culture media. The very 

 lymph from which the specimens of Figs. 159 and 160 were 

 derived was tested by culture and by transference to the calf, 



Fig. 159. — Film Siecimen of Calf-Lymth 72 hours, Clumts of Minute 



Bacilli, 



How minute these bticilli .ire, is shown Ijy the fact that the photo,gram is taken at a 



ma^niiication of jooj. 



and while in this latter it produced typical vaccinia it failed to 

 produce any growth whatever in the culture media (solidified 

 blood-serum, glycerine Agar, ordinary Agar, sugar gelatine, 

 and ordinary gelatine). From these observations I concluded 

 that the above minute bacilli are most pjrobably the microbes 

 of vaccinia. Dr. Copeman, who has worked at the same 

 subject, has completely confirmed the presence of these 



