NATURAL ENEMIES 65 



species of Empusa attacking- other insects, a much 

 greater degree of moisture is necessary, and certain 

 forms occur only in very moist situations. 



In germinating, each hyphal body or resting spore 

 sends out one or more hyphae, which grow with great 

 rapidity, but the manner of this germination, together 

 with the subsequent development of the resulting hy- 

 phse, varies considerably with different species and un- 

 der different conditions. In the simplest case a single 

 hypha thus produced may grow directly to the outer 

 air and then produce a single conidium or set of con- 

 idia. In other cases a single h3^pha may branch indefi- 

 nitely, each final branch bearing a conidium or conidia. 

 This usually happens where the conditions of growth 

 have been very favorable, and the complex may be 

 found side by side with the more simple form. 



The conidium or spore is formed by budding from 

 one of these hyphse, which in this case is called a con- 

 idiophore. This bud increases in size and becomes 

 separated from the conididphore by a cross-partition. 

 Within the mother cell thus formed is developed a 

 single spore. When this cell increases in size by the 

 absorption of water, the wall of the mother cell be- 

 comes separated from that of the conidium and some- 

 times to such an extent that the conidium is seen float- 

 ing free in the large spherical mother cell. Finally by 

 a rupture the conidium is discharged violently into the 

 air, often for a considerable distance. With Empusa 

 muscce, the conidia are bell-shaped or nearly spherical, 

 with a broad base and a measurably pointed apex, 



