176 



PHYCOMYCETEAB 



Fig. 62. Entomophthorales, Family Entomophthoraceae. Sexual reproduction. 

 (A-E) Basidiobolus ranarum Eidam. (F-H) Entomophthora sepulchralis Thaxt. (I-K) 

 Entomophthora fresenii Now. (A-C, after Eidam: Beitr. Biol. Pflanz., 4(2):181-251. 

 D-E, after Fairchild: Jahrh. wiss. Botan., 30:285-296. F-K, after Thaxter: Mem. 

 Boston Sac. Natural History, 4(6):133-201.) 



mophthora, must be used. The internal organs of the host are dissolved, 

 presumably by enzymes secreted by the fungus. The mycelium may be 

 quite extensive and filamentous with only occasional septa or may be- 

 come septate at frequent intervals or break apart into numerous hyphal 

 bodies. The clavate conidiophores emerge through the thinner parts of 

 the body wall of the insect and shoot off their conidia with great violence. 

 The conidiophores may be simple and packed together in a palisade layer 

 or they may be branched at the base. In the latter case the conidia are 

 uninucleate, in the former they are plurinucleate. Both azygospores and 

 zygospores are known in this genus. It is not settled yet whether only 

 one pair or several pairs of nuclei are functional, nor is it known at what 

 stage of development of the zygospore the nuclei fuse. E. muscae (Cohn) 

 Fresenius is the freciuent cause of the death of house flies (Musca domes- 

 tica) in the autumn months. The affected flies cling to window panes and 

 other objects and die there, and the glass immediately surrounding them 

 becomes whitened by a halo of discharged conidia. True zygospores are 

 unknown but azygospores are produced abundantly in Europe but very 



