226 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



tion to silkworms, imported from Japan and other countries, and 

 the food most suited to their keeping. 



Dr. Trimble said it is not necessary that we should import 

 worms from Japan, or any other country, to make silk. We have 

 several varieties, which are natives of this country. They may 

 be found by any one at night, for they are moths, which fly at 

 migl^t — not butterflies, which fly in the daytime. There are four 

 species noticed particularly : first is the Cecropia, which feeds 

 upon the apple, cherry and plum trees of our country ; second is 

 the Polyp/ieme, which feeds upon the oak and lime, or basswood 

 trees ; third is the Ju7ia, which feeds upon the walnut or hickory 

 tree, and the fourth the Promethea, which feeds exclusively upon 

 the sassafras tree. These worms have the same enemies, how- 

 ever, as others — the ichneumon flies — to which we are so much 

 indebted in large cities, where there are no birds, for the destruc- 

 tion of worms that would otherwise trouble us. The idea of the 

 Emperor Napoleon, in importing worms from Japan, is to produce 

 a silk cloth to clothe his soldiers with, so strong and cheap that 

 one suit may last through several generations of soldiers. The 

 Chinese used to hand down the clothing from one generation to 

 another. This was made from one particular kind of worm, which 

 is probably the kind of worm that Napoleon is trying to intro- 

 duce. In the southern part of the East — for instance in Madras — 

 the silkworm goes through its transformations in forty days. 

 Most of the insects native to this country, which have been men- 

 tioned, come at precisely the time that the leaves come. The 

 parent insect will deposit her eggs invariably upon the tree so 

 that they will come out at the exact time that the leaves appear. 

 At Madras the insect is six days an egg, twenty-two days a worm, 

 eleven days a grub, and one day a moth, so that in its perfected 

 existence it lives but a single day. There, of course, the manage- 

 ment must be hurried. We have worius that do not feed on the 

 mulberry tree. The speaker could not say whether they are as 

 good, as few experiments have been made on the subject. The 

 mulberry tree seemed to have been especially intended for this 

 silkworm, as no other insects live upon it. 



Dr. Holton read from a French periodical, on the subject of the 

 silkworm, imported from Caj^enne, and which feeds on the ailan- 

 thus tree. Ihe tree upon which the worm originally fed was the 

 Cafe diable, but after feeding for some time on the ailanthns, if 

 it is then placed upon its native food it will leave it and die of 



