704 



MEDICAL MYCOLOGY 



natural groups of species. Wright (1905) would reserve Actinomyces for 

 anaerobic organisms, placing the aerobic forms in Nocardia. This separation 

 has been widely adopted with varying nomenclature, but is often difficult to 

 apply in practice. I have used this character in my key, although I have kept 

 all the species in Actinomyces. Chalmers & Christopherson (1916), followed 



Fig. 118. — Acivnomyces scabies (Thaxter) Gussow. 1-6, successive stages In the develop- 

 ment of sporogenous branch ; 7, portion of aerial mycelium, some lateral elements bearing 

 secondary branches developed successively, with an unusually long chain of spores (1-6 X 8,000 ; 

 7 X2,750). (After Drechsler 1919.) 



by Castellani & Chalmers (1919) and Froilano de Mello and coworkers (1918, 

 1919) have divided the genus into saprophytic and parasitic species. While 

 this might be useful, if only the obligate parasites are included in the parasitic 



