I04 



MYCOLOGY 



Basidiobolus on Ihe feces of frogs. Non-sexual reproduc lions is mainly 

 by means of unicellular conidiospores which are discharged forcibly 

 from the ends of tubular conidiophores. Sexual reproduction is by the 

 conjugation of two gametes dissimilar in size, heterogamic and thus these 

 fungi connect the ZYGOMYCETALES with the OOMYCETALES 

 where oogamous reproduction is displayed. The zygospores formed 

 in conjugation are spheric, while the azygospores formed on the 

 mycelium without copulation are similar to the zygospores in struc- 

 ture and appearance. The family includes seven genera, includ- 



FiG. 34. — Fly cholera fungus (Empusa musca). 1, Fly enveloped in mycelium; 

 2, fungus between hairs of the fly; 3, conidiophores and conidiospores; 4, germina- 

 tion of spores; 5, formation of egg in Empusa sepulchralis. (After Thaxter.) See 

 Henri Coupin, Atlas des Champignons, Parasite set Pathogenes de 1' Homme et des 

 Animaux, 1909. 



ing Empusa and Entomophthora, which may be chosen as types for 

 discussion. 



The mycelium of Empusa musca (Fig. 34) is parasitic in the 

 bodies of flies, destroying them in large numbers by an epidemic in the 

 fall, known as fly-cholera. The short hyphae frequently bud like 

 yeast cells. The conidiophores break through to the surface of the 

 insect's body, where the conidiospores 18 to 25^ broad by 20 to 30/i 

 long are forcibly discharged. These spores bore their way through the 

 chitinous covering of a healthy fly by means of a germ lube and the 



