ENTOMOPHTHORALES (ANCYLISTES) 



1063 



capable of fornung such a structure. A globose corudium develops at the 

 apex of the conrdtophore, the tip of which forms a ^J^™ 

 projects tnto the conidium. After vacuohzatiou phenomena simila to 

 those descnbed for Comdiobolus and other members of the family see 



^l\rilT f ace ' the conidium is forcib * shot onlTL'Z 



ffig.91F,p 1066), often traveling asfar a, two millimeters ma horizontal 



dtrectton Upon germination, if its germ tube ,s under water, a hypha 

 forms which may accomplish infection (Fig. 91). If the tube extends 

 through the water film into the air, however, a secondary conidium 



okectly 5 ' may e " her te diSCharged like the first or S^nrinate 



Sexual Reproduction 



Because the crowded conditions prevailing in the host cell make obser- 

 vation difficult reports on certain aspects of sexual reproduction in 

 Ancyhstes are somewhat contradictory. All accounts agree that there is 

 conjugation between the mycelial segments. Pfitzer's (1873) observations 

 on Ancyhstes closterii clearly indicated that in his material scalanform 

 conjugation took place between segments of two separate thalli all the 

 segments of one filament being wholly contributory and all those of the 

 other wholly receptive, with the zygotes formed within the latter. Berdan 

 (1938), on the contrary, describes conjugation in this same species as 

 either scalanform or lateral with the gametangia developing simulta- 

 neously as outgrowths from the hyphal cells. From continuous study of 

 the development of a single thallus, she presents good evidence to the 

 effect that actually the hyphal strand elongated, doubled back (at the 

 opposite pole of the host) and grew parallel with its original element. 

 Along these parallel strands, after segmentation, instances of both sca- 

 lanform and lateral conjugation were observed. Couch's (1949) obser- 

 vations on conjugation in A. netrii are somewhat inconclusive, due no 

 doubt to the aforementioned crowding within the host. He states, 

 however, that conjugation is scalariform and that the zygotes mature 

 in the conjugation tubes formed between thallus segments (Fig. 9 ID). 

 Whether the zygote at maturity is to be called a zygospore or an 

 oospore is also a matter of dispute. Berdan (loc. cit.) reports that in 

 Ancyhstes closterii conjugation is clearly zygomycetous, but that in A . 

 berdanii^A.pfeifferr Beck) there is a tendency for the protoplast of the 



