106 



MEDICAL MYCOLOGY 



by the formation of a many-layered wall. This spore is called a zygospore. 

 In the homothallic species when the copulating branch finds no mate, the 

 gametangium surrounds itself with a thick many-layered wall and is called 

 an azyg-ospore or, less properly, a chlamydospore. The same thing happens 



Fig. 9. — Zygospores. 1, Ahsidia glauca (after Lendner) ; 2, Mucor hiemalis (after Lendner 

 1908) ; 3, Parasitella simplex (after Burgeff 1924) ; -i, Zygorhynchus heterogamus (after 

 Blakeslee 1913) ; 5, Rhizopus nigricans (after Bary) ; 6, Sporodinia ginndis (after Bainier 

 1882) ; 7, Phycomyces nitens (after Van Tieghem & Lemonier) ; 8, Spinellus fusiger (after 

 Bainier 1882) ; 9, Mucor racemosus (after Bainier 1883) ; 10, Circinella spinosa (after Bainier 

 1882). 



if the cultures are placed in an unfavorable environment, such as high tem- 

 peratures. In the heterothallic forms, similar phenomena may occur if the 



