Oct. 19, 188S.] 



SCIENTIFIC NEWS. 



411 



Natural f^tetoru* 



A CURIOUS FUNGUS. 

 The dietetic relations of animals and plants are not yet 

 thoroughly known. Every one is aware that there 

 are animals which seize upon some other animal or 

 some plant and devour it entirely an'open, straightforward 

 manner. We are equally familiar with the fact that 

 other animals live parasitically ; they introduce their ova 



late Charles Darwin, as well as other naturalists, has 

 called attention to the so-called "carnivorous plants" 

 which capture insects and consume them bodily. But 

 a less known case is that of a plant, generally of very 

 humble rank, which lives parasitically upon some animal, 

 and appropriates its body. 



One of the simplest instances of this kind 01 parasitism 

 is when an ordinary mould attacks some living insect in 

 the larval or pupal stages. Entomologists, in searching 

 for the pupae of moths, whether in the earth or among 



Cordyceps Robertsii, growing from the Pupa of Charagia virescens. 



into the bodies ot other animals or of plants, these ova, 

 when hatched, preying gradually upon their host, ab- 

 sorbing its juices, and in many cases destroying it out- 

 right. Such parasites are the intestinal worms which 

 haunt man and the lower animals, the "warbles" which 

 perforate the hides of cattle, the ichneumons which in- 

 sert their eggs into caterpillars, the weevils which in like 

 manner oviposit in the buds of plants, so that the young 

 grub may prey upon what should have been the fruit. 



But it is less generally known that there are plants 

 which turn the tables upon the animal creation. The 



decaying vegetation, not unfrequently find them invaded 

 by mould ; such specimens, of course, come to nothing. 

 A much more decisive and instructive case is that of 

 the " fly-fungus " (Empusa muscae). In autumn we may 

 occasionally perceive sitting on the window-pane a common 

 house fly, with which there isdecidedlysomething amiss. Its 

 movements are feeble and sluggish, and at last it seems 

 to become fixed to one spot, where it dies. The glass 

 around it appears to be covered to the extent of perhaps 

 a quarter of an inch with a whitish film. If the observer 

 can persuade such a fly — as we have done more than 



