ENTOMOPHTHORALES 285 



break up into oidia, which are regarded as comparable to the 

 hyphal bodies commonly developed elsewhere in the family. 



In asexual reproduction, slender erect sporangiophores are 

 raised above the substratum, each becoming apically inflated to 

 form a clavate termination recalling the subsporangial vesicle 

 of Piloholus. From this a terminal bud is put out which enlarges 

 into a pyriform sporangium ("conidium"). The sporangium 

 is uninucleate, and finally is discharged with violence from 

 the sporangiophore. Preceding discharge a portion of the tip 

 of the subsporangial vesicle is differentiated by contraction and 

 the assumption of a thicker wall to form a conical structure, 

 termed the "basidium," immediately beneath the sporangium. 

 This "basidium" is carried away with the sporangium when dis- 

 charge occurs, rupture of the apex of the subsporangial vesicle 

 being transverse. Later the two fall apart. At the time of 

 discharge sporangiospores have not yet been formed. 



Until very recently the phase of the life cycle of B. ranarum 

 which precedes the appearance of the mycelium in the excrement 

 was wholly unknown. In an able investigation Levisohn (1927) 

 has now shown that the sporangia, after being shot away from 

 the sporangiophore, are eaten by beetles, and that these in turn 

 are devoured by frogs. In the alimentary tract of the frog the 

 sporangium undergoes further development. Its nucleus divides 

 several times, and thin-walled non-motile sporangiospores are 

 cut out. The number is often eight. These spores escape 

 by the disintegration of the sporangial wall, and lie free for 

 a time in the body of the frog, multiplying there by fission. Only 

 after reaching the outer air are they capable of germination to 

 form mycelium. In culture under optimum conditions the 

 sporangium germinates by forming endogenous spores, but more 

 commonly it functions as a conidium and sends out germ tubes 

 directly. 



In age, the mycelium forms zygospores. Conjugation takes 

 place between adjacent cells of the same hypha. Since the cells 

 are uninucleate it is not unlikely that their nuclei are sisters. 

 This close relationship may explain the rather peculiar and 

 apparently unnecessary phenomenon which follows. At the 

 point where the zygospore is to be formed a beak-like protrusion 

 is pushed out on each side of a transverse septum. These beaks 

 grow in lateral contact until a considerable length is attained. 

 In each case the nucleus of the parent cell migrates out into 



