46 . 



as it was, except two mature caterpillars of Oregonia discovered, 

 nothing whatever was done towards the biology of any of the spe- 

 cies treated of in the Doctor's paper. The entomological party 

 seem to have been in the field ten to fifteen days, from June 

 24 to July 5, and were on the wing all the time, but brought home 

 a large lot of butterflies of various species. The results of that 

 excursion seem to have aroused in our friend an enthusiasm 

 that will not be restrained, and it is clear he dreams of oversetting 

 the work of a score of lepidopterists who have gone before him, 

 and of constructing on the ruins a sort of Ptolemaic system of 

 arrangement of our species. I would not say a word, if this 

 system were to be based on the preparatory stages of the several 

 species, but that does not enter into it at all. What the system 

 may probably be in its details is shadowed in a remark in a letter 

 to me from the Doctor some time this winter, that after having 

 worked a number of weeks on Colias, he "is getting the tvhole 

 series into three or foiir species,^'' * i. e., the North American Colias, 



As there are something over a couple of dozen species of 

 Colias claimed to belong to our fauna, of only two of which, out- 

 side of Cccsonia and Etirydice, are the preparatory stages at all 

 known, this is evidently a weighty piece of work. All I wonder 

 at is, that my good friend should stop at three or four, when it 

 is just as easy to say one, and have all the species rank as vari- 

 eties of that; as Colias Priniordia,M2iX. EnrytJienie ; var. PJiilodice. 

 Really, I admire the zeal displayed and sympathise with the en- 

 thusiasm, but I must refuse utterly the conclusions reached by 

 the Doctor. I have not much hope, however, that anything I 

 shall say will alter his views. When a Professor of Biology, even 

 with but a moderate acquaintance with butterflies, can deliberately 

 declare that " it is probable that P. Brevicatida, Bairdii, Indra^ 

 Pergamns and probably Aviericiis^ belong all to P. Asterias^' I fear 

 he is past praying for. I write then not so much for him, but for 

 a younger generation, who have grown up under more liberal 

 teaching. 



I hold that every permanent form possessed of marked char- 

 acters which distinguish it from other forms, and which breeds true 

 to its type, so far as appears, or we can know, is to be regarded 

 as a species, at least, till the contrary is proved. And the proof 

 must be actual, not imaginary, facts, not guess-work. That this 

 is directly opposed to the view which can lump species into one, 



* The lepidopterists of Europe are not agreed as to the position of divers of their own species of 

 Colias, though 150 years have passed since Linnaeus, during which time many generations of active 

 workers have come and gone in every country. No one can say to-day what are the relations between 

 C. Palieno and C. Pelidnt\ or if there be any at all ; and, for all that matter, no one will be able to 

 speak with knowledge till Ijoth forms have been bred from the eggs laid by the respective females. All 

 investigati ns which begin and end with the dried butterflies in cases of doubtful and obscure species 

 amount to nothing. One may argue forever from the butterfly and be no whit nearer real knowledge 

 of the facts. And now, what has not been done in Europe in five generations, our earnest friend 

 thinks he can do with the American Colias " in course of a number of weeks" inside tho walls of the 

 Cambridge Museum. I recommend a tent in the field for a few seasons, and hard work, with much 

 fatigue and many disappointments, but with patience to overcome all;then we shall begin to see results • 



