FIELD AND FOREST. 43 



fatty parts of the caterpillar. Our common house-fly yields its life to 

 a white mould, and when seen standing lifeless, covered with its para- 

 sitic dress, one might suspect that it had just returned from a ramble to 

 the flour box. 



Beetles that deposit their eggs in the crevices of locust trees and their 

 grubs that feed upon the wood ; also those that live in the neighborhood 

 of woods inhabiting old trees; and those feeding upon Agarics and 

 Boleti are, in their turn, particularly inviting to fungi. We have often 

 met with them standing erect or otherwise, hard and dry, ready to 

 crumble at a touch, and sometimes emitting a peculiar fungoid odor. 

 This is the work of fungi. Again, we have observed caterpillars in the 

 full process of feeding, apparently strong and lively, with fungi sprout- 

 ing out in hornlike projections about the head, which part seems to be 

 a favorite nidus. 



We cannot think that this arises from any peculiar power of selection 

 on the part of the fungus. We know that in parasitic insects the 

 female seems to have an instinctive knowledge where to place her 

 eggs so that the larva will be nourished. But they being endowed 

 with acute senses and possessing animal life are a step higher than 

 fungi. Perhaps it may be that, in most cases, the head of the worm 

 in feeding first comes in contact with the spores, and they finding 

 congenial soil vegetate ; or the spores may be taken in with the food. 

 The whole insect is sometimes covered not only with a species of 

 Clavaria, but with a mould not unlike that which attacks the house-fly. 

 After the mycelium has taken possession an inexperienced person might 

 think that life in the leaf world had closed, that the fungi were horns, 

 but we see no preparation of silken web for cocoon life ; the worm is 

 positively dead. The size and power of the insect may lengthen its 

 days, but it rapidly yields itself to the invasion of a parasite, becomes 

 motionless, hard and dry, crumbling into dust upon the slightest 

 pressure. 



These cases of fungi upon living insects are not of frequent occur- 

 rence, and are usually met with upon those which feed upon weeds in 

 secljded places. We have observed that a very tropical summer, 

 coupled with a humid atmosphere, is the rule. Several seasons may 

 pass without finding one affected. 



We have sometimes been able to detect the presence of the Melolon- 

 tha, commonly called the cockchafer, or May-beetle, by a sprout rising 



