lOO GENERATION OF INSECTS 



have never found two. The worm is white, without 

 legs, and is conical in shape, like those produced by flies, 

 which I described in the beginning of this letter ; as long 

 as it remains in the worm stage, it is solely occupied with 

 feeding and growing, but does not make any abdominal 

 secretions ; when it has reached a certain size, it leaves the 

 cherry in which it was born, and seeks a place to settle 

 down, and here, little by little, it shrinks, hardens and is 

 changed into a small, milky white egg [pupa] from 

 which nothing hatches for a year, when, on the arrival 

 of Summer, a small fly escapes from it, which is black 

 and hairy ; the hairs on the head and back, though rarer, 

 are longer than those on the belly; on the back there is 

 a half-circle of a gold color, and the head is striped with 

 yellow also, from which proceeds a similar large streak 

 of color, that covers a large part of the space between 

 the eyes; the wings are white and covered with gray or 

 black spots, so beautifully arranged that they resemble 

 falcon feathers; there are six legs, also black, hairy, 

 and touched with gold at the joints. You will be able 

 to have a better idea of it from the accompanying draw- 

 ing, in which the worm is shown together with the 

 chrysalis into which it is changed and the fly, that 

 hatches from it; these appear in natural size and also on 

 a larger scale, as viewed through a microscope of one 

 lens. 



Very different from the cherry worms, are those 

 which are found in green filberts, for these are shaped 

 like a half cylinder and composed of white semicircles; 

 the head is auburn and shiny; they do not move quickly, 

 and have six very small legs, placed in three rows near 

 the head. I have never been able to observe the trans- 

 formation of these worms into winged animals; hence 



