98 



The chrysalis of Virginiensis as appears by the colored drawing 

 spoken of is of precisely the same shape as that oi Olcracea. It has 

 a minimum of black dots over its surface. On the other hand the 

 chrysalis of Bryonies from Newfoundland shows a maximum of 

 these dots, and several little dusky clouds or spots, as might 

 be expected from the clouded and spotted wings which are to is- 

 sue therefrom. The chrysalis of Vcnosa, from California, comes 

 next to Bryonies in these marks : that of Olcracea var. Borcalis, 

 from Anticosti, having few marks, like Olcracea in New York. I 

 have drawings of all these ; and of all but Virginie^isis have 

 preserved chrysalids also. There is not the least difference in 

 shape in these chrysalids. 



We are now prepared to tabulate the American forms derived 

 from Bryonies, and I contrast them with the corresponding Euro- 

 pean forms : 



EUROPEAN. AMERICAN. 



1. Arctic form BRYONIA, Ochs. i. Arctic form BRYONIA, Ochs. 



var. HULDA, Edw. 



2. Winter form NAPI, Esper. 2. i. Winter form VENDS A, Scud. 



Nasturtii, Bois. 



aberr. 2 flava. 

 2. Winter form OLERACEA HYE- 

 MALIS, Harr. 

 Oleracea, Bois. 

 var. A. BOREALis, Grote. 

 " B. FRIGIDA, Scud, 

 aberr. VIRGINIENSIS, Edw. 



3. I. Summer form ACADICA. 



2. Summer form a. PALLIDA, 



Scud. 



i^. ^ CASTORIA, 

 Reak. 

 aberr. flava. 



3. Summer form OLERACEA ES- 

 TIVA, Harr. 



Casta, Kirby. 

 Cruciferarum, 

 Bois. 



4. Species (Southern) VIRGINIEN- 

 SIS, Edw. 



I believe this to be an accurate statement of the phases 

 of the American forms derived from Bryonies, and it is 

 based on my own acquaintance with them. Not being so 

 familiar with the European derived forms, and restricted to des- 

 criptions, plates, catalogues and such specimens as I could collect 

 by the aid of friends, I can only give the three principal and 

 well-known manifestations, doubtless omitting some important 

 variations not named. But the general statement on one side, 

 and the particular one on the other, are sufificient to show how 

 climate and environment affect the descendants from a common 

 parent-form. How the differences, at first slight, gradually become 



3, Summer form NAPyE^, Esper. 



