An Insect Virus 



find, laid on a sheet of white paper, on which 

 the urinary fluid of the perfect insect will fall 

 as soon as the caskets are broken. 



The weather is favourable and I have not 

 long to wait. The thing is done: the mat- 

 ter rejected is white, the usual colour of these 

 residua, in the great majority of insects, at the 

 moment of the metamorphosis. Though by 

 no means abundant, it nevertheless provokes 

 on my fore-arm a violent itching, together 

 with mortification of the skin, which comes 

 off in flakes. The reason why it does not dis- 

 play a more distinct sore is that I judged it 

 prudent to end the experiment. The burning 

 and itching tell me enough as to the results of 

 a contact unduly prolonged. 



Now to the Hymenoptera. I have not in 

 my possession, I regret to say, any of those 

 with whom my rearing-chambers used for- 

 merly to provide me, whether Honey-bee or 

 Hunting Wasps. I have only a Green Saw- 

 fly, whose larva lives in numerous families on 

 the leaves of the alder. Reared under cover, 

 this larva provides me with enough tiny black 

 droppings to fill a thimble. That is sufficient: 

 the urtication is quite definite. 



I take next the insects with incomplete 



183 



