OF NORTH AMKRICA. 139 



H. tessellaris, Sm. Abbott, which he calls phvtophagic species, and 

 which are founded on a varying color of the hair, pencils and a 

 different food plant. If these larval differences were accompanied by 

 differences in the imago, the position would be tenable, but this 

 author admits the absolute identity of the imagines raised from larvas 

 of both classes of coloration. It seems then, that however pertinent 

 these observations may be to the question of the origin of species, the 

 contingencies of the early life of the larva have as yet produced no 

 result upon the imago, and until such proves to be the case we are 

 scarcely warranted in creating new species on differences in larval 

 coloration. Indeed, the position taken by Dr. Walsh is not yet 

 proven. He does not show that larva; raised on the Sycamore, pro- 

 duce imagines, the eggs from which evolve identical larvne, and 

 similarly of larvre raised on the oak. While not absolutelv establish- 

 ing his proposition, this would have materially strengthened his 

 argument, but it does not appear that this phase of the experiment 

 was ever undertaken. I cannot better sum up this question than in 

 the words of Mr. Grote, who says, (Proc. Ent. Soc. Phil. vol. 3, p. 

 536), in relation to H. aniiphola, Walsh, "The validity of the sup- 

 posed species rests upon a stated difference of larval structure affect- 

 ing the location of the 'hair pencils,' a different coloration of the 

 latter and a varying food plant. Subsequent investigation, I am 

 informed, has contradicted the hrst of these asserted differences, which 

 indeed, on the supposition that it existed, would rather indicate a 

 generic than a specific character, and I consequently omit any further 

 remarks upon it. There remains then a differing coloration of the 

 larval 'hair pencils" and a differing food plant as the totality of 

 specific characters which are to constitute the new species. Analagous 

 instances of larval variation in the coloring of the ' hair ' among 

 members of the present family have been discovered without having 

 been made the basis for the description of a new species, and may be 

 correctly regarded as simple variations within the 'well defined limits 

 of the species,' while the habits of the differing larvae as to the food 

 plant, especially in such an essentially polyphagous family as the 

 Arctiidae, can with difficulty be drawn in as a specific character, even 

 upon much more perfect and detailed evidence than Mr. Walsh has 

 offered in the present instance. * * * It is not the most 



inconsistent part of Mr. Walsh's paper, that while H. antipliola is 

 published as ' N. Sp.,' it is regarded on page 298, (Proc. Boston Soc. 

 Nat. Hist. February, 1864,) as merely in process of 'formation." No 



