105 



familiar manner in wliich tliey solicit honey-dew from Aphides. 

 Although search was made for beetles, only a single specimen 

 of T^nesijyhorus costalis was found in the nests. 



Mr. McCook was unable to obtain any show of fight between 

 these ants, excepting that individuals which had fallen into 

 water (which is supposed to destroy their odor) were always 

 attacked violently by their confreres. Every expedient was 

 tried : colonies from distant hills were thrown upon a nest 

 while it was covered with a swarming and nervous mass of 

 ants, without the least effect : not the slightest sign of hostility 

 could be induced ; the imported ants always melted away into 

 the general community as if at home. These are the principal 

 observations offered by Mr. McCook, which we hope he may 

 continue in the same spirit. Our ants offer a fruitful field of 

 observation to those who have the leisure to observe them. 



The only remaining insect, whose history has this year been 

 given in full, with the exception of injurious species, which I 

 reserve until the end, is our common Platysamia cecropia, of 

 which Mr. T. G. Gentry has given a detailed description in all 

 its stages. 



In a paper on the classification of butterflies I have given 

 generalized histories, as it were, of the different family groups, 

 of which four are recognized ; and I have attempted to exhibit 

 the comparative inferiority of structure of the swallow-tails, 

 bringing forward several considerations hitherto unnoticed, 

 some of which may be briefly stated : the four-branched 

 median nervure, supposed to be peculiar to the swallow-tails, 

 exists also in the skippers ; the osmaterla are paralleled by 

 similar organs in all other butterfly larvas, and these being 

 exceptionally developed, as tentacles or caruncles, in several 

 special groups of in-'-ects, have no structural significance ; the 

 swallow-tails are most nearly allied to the Pierids, but the lat- 

 ter group possesses none of the characters on account of which 

 high rank has been claimed for the swallow-tails ; on the other 

 hand the swallow-tails are directly allied to the skippers, the 

 lowest family of buttei'flies, by the form of the egg, the dorsal 

 shield of the first thoracic segment in the larva, the cliai-acter 

 of the silken attachments of the chrysalis, and by various 



