270 



Shell of the 

 ichneumon fly. 



The anlmat 

 cotton is white 

 and pure ; 



ON ANIMAL COTTON, OR THE INSECT FLY-CARRIER. 



now appears flabby, wrinkled and dirty, and give! him the 

 appearance of decrepitude. He is now an exhaufted, flitter- 

 ing being, threatened with approaching death. 



He will ftill gnaw a few leaves, but he no longer cats with 

 that voracious appetite, which indicated an a6tive and vigo- 

 rous conftitution. Shortly afterwards he paflfes to the ftate of 

 a chryfalis, and after giving life to thoufands of eggs, he fud- 

 denly lofes his own, leaving to the cultivator who has not yet 

 bethought himfelf of calculating the advantage that he may 

 draw from him, an advantage which may be fo improved as 

 to much more than compenfate the ravages which he occafions. 



Shell of the Ichneumon Fly, 



I had imagined that the thoufands of little worms which 

 this fhell contains in the cocoons of which it is compofed, 

 would be hatched fome day. I fhut it up therefore in a box 

 clofed with great caution. Every morning, and very often in 

 the courfe of the day, I examined it, in order to catch the 

 moment when thofe little animals were to be born a fecond 

 time. 



In fa6l, at the expiration of about eight days, I found the 

 infide of the box lined with a cloud of little flies. I made 

 myfelf certain that they iflued out of the little cocoon. Se- 

 veral which iflued out of them before my eyes, left me no 

 doubt as to the fact. 



I then took up fome of thofe flies, and putting them on a 

 pincer, I examined them with a microfcope. 



They are bold and lively : they have four wings. Their 

 antennae are long and vibrating, their belly hangs by a very 

 fine thread : there are fome that have a tail, and others that 

 do not fhew it. Afterwards I fatisfied myfelf that they feed 

 upon fmall infects that appear to be of the family of Acarus. 

 Thofe indications appeared to me fufficient to be fatisfied that 

 they belong to the family of the ichneumon. 



Obfervations on Animal Cotton. 



I have often held in my hand that cotton fliell or wrapper. 

 Its whitenefs is dazzling. As foon as the flies have quitted 

 the cocoon, it may be ufed without any preparatory precau- 

 tion. It is made up of the pureft and fineft cotton. 



I call 



