254 TEXT-BOOK OF FUNGI 



in the clavate sporangia containing more than one row of 

 spores at the apex. 



Entomophthoreae 



A characteristic feature of the present family is the 

 production of a quantity of stout hyphae with oily or 

 fatty contents. Many of the species are developed on 

 insects, of which the best known is Empusa mustae, the 

 one attacking the common house-fly, which becomes 

 attached to a window-pane, and is soon surrounded by a 

 white cloud of liberated conidia. 



Asexual reproduction is effected by large, colourless 

 conidia, which are elastically projected into the air at 

 maturity. Sexual reproduction, by the conjugation of 

 gametes, often of unequal size, and originating as lateral 

 outgrowths of two distinct hyphae, as occurs in Spirogyra 

 amongst the algae. The resulting zygospore, enclosed in 

 a very thick, hard wall, becomes a resting-spore. Azygo- 

 spores, similar in appearance to zygospores, and acting as 

 resting-spores, are also formed by some species. 



The members of the present family somewhat resemble 

 the Saprolegnieae in habit, but are quite distinct in the 

 mode of formation of the sexually produced resting-spores, 

 and in the conidia not being motile. 



Most of the species are entomogenous or parasitic on 

 insects, but a few forms are met with on fungi, in the pro- 

 thallia of ferns, or on the dung of frogs, lizards, etc. 



Those that attack insects often attach the host firmly 

 to some substance by means of specialised hyphae or 

 rhizoids, the tips of which are often discoid. In other 

 cases the insect is firmly fixed by its proboscis to the 



