444 



ACTJNOMYCETES. 



egg, "Wolff and Israel obtained especially good dichotomous 

 forms. 



Conditions of "Spore-formation." — In many threads 

 (not exclusively, but especially, with entrance of air) 

 there are formed by continued transverse fission, short 

 cocci-like and roundish oval bodies, which sometimes lie 

 in close, but usually in broken rows within the empty and 

 finally torn membrane (Bostrom, Kruse). Before the dis- 

 charge of the ' ' spores ' ' the end of the thread is often some- 

 what swollen. The ' ' spores ' ' stain like protoplasm, not 



Fig. 21. — Bouillon culture of Actinomyces bovis. 



like the endospores of bacteria. We have seen nothing of 

 these structures (Fig. 20, c) in either young or old cultures, 

 although we took much pains to look for them. Typical 

 conidia spores cut off in rows do not appear to be de- 

 scribed. 



Viability and Resisting Properties. — Very old cul- 

 tures (nine months) are still alive. 



Chemical Activities. — They have been but little 

 studied. The odor is very faint, disagreeable but not 

 moldy. From grape-sugar within eight days, neither gas 

 nor acid is formed, and no HjS in peptone bouillon. 



