211 



male of 44. See last page." These drawings represent both surfaces 

 of both sexes very accurately, though the blue is made to occupy ra- 

 ther more of the disk of the wings in the female than it does in my 

 specimen, a variation common in this genus. 



Now that I am on the subject of the American Polyommati, I may 

 just express my opinion that two species are confounded under the 

 name of pseudargiohis, one a northern species, with the markings of 

 the under surface very distinct and coarse, the other a southern one, 

 in which all the markings below are beautifully delicate ; but having 

 taken few specimens in the north, and those all females, I dare not 

 speak positively on this head. The northern species or variety I took 

 at Trenton Falls ; the southern one on the summit of one of the Al- 

 leghanies, between the Warm Springs N. Carolina, and Cave Hill Te- 

 nessee. P. Comyntas was in tolerable plenty at the latter station, 

 and I also took it on the banks of the Ohio. P. Filenus I only found 

 in East Florida, amongst the long tufts of grass on the sandy shores 

 of the St. John's. It was by no means common. 



Edward Doubleday. 



Epping, October 10th, 1841. 



Art. LIII. — Notes on Virey's System of Animal Structure. 

 By Francis Walker, Esq. 



The continual increase of observations made on the structure and 

 habits of creatures renders the study of Natural History — more and 

 more embarrassing by reason of the accumulating heaps of recorded 

 facts, — a useless mass until arrranged under general laws, on which 

 may be raised a magnificent temple of knowledge, crowned and up- 

 held by one universally applicable. The time is not yet come for a 

 discovery which, foretold by Newton, would be as comprehensive as 

 that of gravitation, but the af)proach to it may be facilitated by ap- 

 plying some of the numerous discoveries to the illustration of the laws 

 already established. Among these one of the most general and com- 

 prehensive is, the law according to which the whole creation of ani- 

 mals and vegetables forms an organic pile, having two poles, animals 

 tending toward the positive pole, and vegetables toward the negative 

 pole, when the two kingdoms are compared the one with the other. 



The lowest species of animals and plants differ from the more per- 

 fect creatures by mutually approximating, and having more in common 

 with each other and with inert matter, and with them the positive pole 



p2 



