THE VICTOEIAN NATURALIST. 91 



insects may occasionally be seen, after autumnal rains, dead on 

 the bark of trees, qx portions of various plants, on the ceilings 

 and windows of houses, &c., adhering by means of a whitish 

 fungoid matter, or mould, which seems to have emerged from 

 between the last segments of the abdomen beneath and the joints 

 of the legs. The body and wings also become entirely covered 

 by the same parasite, which, under a high magnifying power, 

 appears to consist of elongated filaments in close contact. When 

 separated from the mass, some are found simple and others 

 terminated by a minute globule ; those upon the wings appear 

 merely globules. These flies, which are in the perfect state, 

 become, while in activity, suddenly overtaken by the effect of the 

 parasite internally, which causes the insect to settle on any object 

 that may be in its way. Death soon after ensues ; and the rapid 

 growth of the parasite having first affixed them by the abdomen 

 and legs to the object on which they had rested, it then develops 

 itself entirely on the outer surface of the insect, and even spreads 

 itself for some distance around it, as may easily be noticed in 

 those seen on windows." Professor Cooke relates the following : 

 — " In the spring of 1884, from the middle of May until the end 

 of the first week in June, all the gardens and fields in the neigh- 

 bourhood of Ottawa were severely attacked by the larvae of 

 Agrotis fennica. The disease pervading these larva was ex-- 

 tremely virulent. Dead larvae were to be found in all directions 

 — on stone walls, on fences, and particularly on the tops of the 

 stems of grasses. The Entomophthora was undoubtedly the in- 

 fluence which brought this destructive insect down again to its 

 normal rare occurrence at Ottawa." 



The fungus in this instance was E. virescens. He describes 

 its appearance as a greenish yellow coating, emerging in small 

 tufts from the body of the insect. The gonidia were oval or 

 oblong with a bluntly rounded base and apex ; colour greenish 

 yellow. 



Turning our attention to the Laboulbeniaceae we find that 

 they can be hardly termed true parsaties, as none of their roots, 

 or hyphse, have been observed to penetrate the cuticle of their 

 host. Dr. Cooke thus describes them : — " They are often 

 found on Coleoptera, adhering to the legs, elytra, and body 

 of the insect. They have no mycelium penetrating the beetle, 

 but are entirely superficial, being attached by a small obconical 

 knob at the base of the stem ; hence they may be carried 

 about by the insect for an indefinite period of time. Their 

 colour is mostly some tint of brown, and their form more or 

 less clavate (club-shaped). The upper portion is occupied by 

 the perithecium, the cavity in which the spores are produced, 

 and these escape by a perforation at the apex. The lower portion 

 is narrowed into a stem, which has two cells, one above the other, 



