232 DISEASES OF THE COTTON PLANT. 
appearance, the young naturalist concludes, of course, that 
the fly is produced by the caterpillar ; whereas the rightful 
tenant of the chrysalis-case had been previously displaced 
and devoured by the larva of the ichneumon fly, which 
was produced from an egg placed by the parent fly in the 
body of the caterpillar. This fact is here noticed in con- 
sequence of some drawings of insects injurious to cotton 
having been sent to the Patent Office, among which an 
ichneumon fly was figured as proceeding from the chrysalis 
of a caterpillar. This was correct, inasmuch as it was the 
parasite which had devoured the chrysalis, but not true 
when intended to represent the perfect insect as naturally 
proceeding from the caterpillar itselt 
Some chrysalides of the cotton caterpillar, which had 
been preserved during the autumn of 1855, as an experi- 
ment to try whether they would live untU the following 
spring, having been hatched out prematurely by the heat 
of the room in which they were kept, two ichneumon flies 
were produced of a slender shape, and about half an inch 
in length ; the abdomen or body of the female was black, 
and marked with seven light-colored, yellowish, narrow 
rings around it ; the head was black, with the eyes brown, 
the antennae long, jointed, and nearly black ; on the head 
were three ocelli ; the thorax was black ; the wings trans- 
parent, of a rather yellowish tinge, veined with black, and 
having a distinct black mark on the outer margin of the 
upper pair ; the first joint of the hind-leg was compar- 
atively large, thick, and of a brownish color ; the thighs 
were also brown ; the tibiae black, with a broad white band 
in the middle ; the tarsi were white, tipped with black ; 
and the ovipositor protruded more than the tenth of an 
inch. The male presented much the same appearance as 
the female, but was more slender in form. 
