ox THE DIFFERENCES HETWERN' riERlS HRASSICK AXD P. rifAniCI.EA. 179 



searched for many years, and passed as many Brassiere through my fingers as 

 would reach ahnost from my residence to yours, still I detected no diflferenee 

 otherwise than usual. 



It so happened that last autumn I stumbled upon what I thought at first 

 sight was a little cluster of eggs of Pieris Brassicce; but it struck me it was 

 not quite the thing, and I brought them home and compared them; there was a 

 great resemblance, still I was not satisfied. In course of time my eggs were 

 hatched, and every one went into a state of chrysalis. The caterpillars differed 

 widely from Pieris Brassicce, the chrysalis also. The perfect insect, every 

 one was Char idea, and the time of appearance was different. Thus the egg, 

 caterpillar, chrysalis, time of appearance, and perfect insect being different; it 

 follows "de necessitate," the two species must be distinct, and Pieris Chariclea 

 is no more a variety of Pieris Brassiere than Pieris Brassicce is of Pieris 

 Chariclea. 



I am not going to describe the difference between the two perfect insects. 

 That is already very fairly done by J. O. Westwood, Esq., in his work entitled 

 "British Butterflies," published in 1S41, in which he quotes from "Albin." 

 Not possessing, nor ever having had the good fortune to meet with "Albin's" 

 work on Entomology, I can form no opinion as to the accuracy of his colouring 

 the caterpillar. It is clear, however, that "Albin" himself was aware of the 

 difference between Brassicce and Chariclea. 



I readily admit that to an unpractised Entomologist so great is the general 

 resemblance of the two caterpillars, that they are probably often passed over 

 or mistaken one for the other. I am almost certain I have formerly repeat- 

 edly done so myself; and I dare say others have done the same. I send you 

 a little synoptical table in which I have, without attempting to occupy your 

 time or space too much, given you the precise points in which these two 

 caterpillars differ, neither more or less; in all other respects then please to 

 observe the two caterpillars present the same appearance. 



I cannot help thinking that Pieris Chanclea is a much less common insect 

 than Pieris Brassicce, but it would occupy too much of your space to give 

 my reasons for so thinking, and also I believe that many Entomologists have 

 placed in their collections an accidental variety of Pieris Brassicce for Pieris 

 Chariclea. I know T have formerly done so my.self, but now I have not the 

 slightest shade of hesitation in pronouncing Pieris Chariclea to be a perfectly 

 distinct species from Piens Brassicce. 



I trust this may interest some of your readers, and lead them to follow up 

 this and similar cases, and I hope to see the results of their observations in 

 your Journal. 



POINTS OF DIFFEREXCR OF (JATERPILLARS, 

 P. Brassietr. P. Chariclt^a. 



Ground colour. — Pale grayish sea-green, or Ground colour. — Pale greenish yelknv, (in~ 



pale grayish yellow. variably.) 



Abdomen. — Dull )'ellowi8h green, with a Abdomen. — DulH««o«-rc/oMr, with a rather 



rather darker ventral line. lighter ventral line. 



