204 



between species re])iited for their suluciuus liuljits, us between birds in 

 the Gallinae and Passeres, between fishes in the Cyprinoiih. Now 

 every one will agree tliut the luibit of tlic Jioinhyccs is salacious in 

 the highest degree. 



There is perhaps another circumstance in favor of my conjecture. 

 The hybrids of Tetrao urogalliis and tetrix, known as Tetrao inter- 

 media, occur notoriously always, when, by excessive hunting, the 

 males of the first are killed in such a number, that the females are 

 obliged to recur to the other species. Now it is not improbable that 

 in times Avhen some si)ecies of Attacus are extensively damaged by 

 parasites — and I beg to remark tliat in the year Mr. Smith reared 

 his specimens, all cocoons but three of Columbia, were most exten- 

 sively attacked by parasites — the interbreeding would be much facili- 

 tated; I remarked also that, in the same year, Mr. Smith presented to 

 the Museum a large lot of parasites bred from Polyphemus, and 

 the year before of Cecropia, as proof that at least those species 

 were largely infected. 



The idea that new species may be formed by interbreeding is a 

 very old one, even expressed by Fabricius in one of his first books, 

 Philosophia Entomologica, by Gravenhorst in his celebrated work 

 on Ichneumons, and by Westwood. 



However it may eventuate, the conjecture that Columbia could 

 be a hybrid species, seems to me at least worthy of consideration. 



Concerning another new species, Gloveri, I cannot help thinking 

 it to be identical with Columbia, to judge from the figure and de- 

 scription, as I have not seen the specimens. It is fair\o state that 

 Mr. Strecker, on seeing our specimens of Columbia, declared them 

 to be different from his Gloveri. 



Concerning the previous stages of Columbia, Mr. Bowles captured 

 in August a full grown specimen, so closely resembling a Cecropia 

 caterpillar in size and general appearance, that he did not take 

 notes at the time, though on close examination he could not quite 

 reconcile the color and arrangement of the tubercules with the 

 description given by Morris. The principal difference was in the 

 number of red warts, Columbia possessing more than the other 

 species: The remains in our collection show the head, tail and the 

 warts of the thoracical segments as in Cecropia. More is not to be 

 seen. Another specimen has also the abdominal warts, but discon- 



