351 



be easily spanned. The reason why the moth cannot pass this partic- 

 ular angle seems to be, that, in passing from one piece of zinc to the 

 other, she has to move sideways, and thus support herself on three 

 legs, on the rim, while she endeavors to get the other three on the 

 band ; and, as her weight is too great to be thus supported, she falls 

 fi-om the zinc in the attempt. Mr. Ordway thought, that, if she only 

 had another pair or even longer legs, she could get over easily enough. 

 It would be interesting for the supporters of the development theory to 

 try to develop the legs of this insect to the required length or nmnber 

 necessary for the purpose. It was ascertained that the weight of the 

 females was the principal reason of their not being able to pass over 

 the angle ; as, after they have laid their eggs, they can pass readily 

 enough. Mr. Putnam saw hundreds of the insects try to get over the 

 angle; but every one failed in the attempt. After dropping once or 

 twice, they are so much injured thai? they do not have the strength to 

 try again, and soon die where they fall ; or, as as a last effort, deposit 

 their eggs on the trunk of the tree, below the protector. Mr. Putnam 

 saw several drop just as soon as the antennte were brought in contact 

 with the second piece of zinc, thus showing the extreme sensitiveness 

 of these organs. It will be interesting to know the exact angle that 

 is required to prevent the insects from crawling over ; and he had re- 

 quested Mr. Ordway to measure it. Mr. Ordway thought that the 

 canker-worms did not leave the earth until after a frost, and that 

 the average life of the female insect was about eight days. The male 

 insect he had found crawling up the trees before its wings were ex- 

 panded. Mr. Ordway had never found the pupae in the eai'th below 

 six inches, or above two. The female canker-worm will never at- 

 tempt to crawl under an obstacle when she can crawl over it ; but, if 

 she is prevented from crawling over, she will squeeze herself through 

 a very small space, if it is large enough to get her head through, 

 though the body is much larger than the head. 



The following letters, which had been recently received, 

 were read ; viz. : — 



From the Royal Society, London, Aug. 13, 1863, acknowledging 

 the receipt of the Society's publications; the Societe Geologique de 

 France, May 25, 1863, communicating certain changes in its rules with 

 regard to papers laid before that society ; and from C. H. Hitchcock, 

 Quebec, Oct. 29, acknowledging his election as a Corresponding 

 Member. 



Mr. A. S. Packard, jnn., was elected Curator of Crustacea. 

 Prof. William Haidinger, of Vienna, was elected an Hon- 

 orary Member. 



Mr. Charles A. Stearns was elected a Resident Member. 



