C 5G7 



XV. On the Phylogeny and Ecolution of the Lepidoptera 

 from a 'pupal and oval standpoint. By Dr. Thomas 

 Algernon Chapman, M.D., F.E.S. 



[Read June 4th, 189G.] 



The title of this paper is perhaps too ambitious, and 

 would require a volume rather than a short paper to 

 elucidate it. It is incorrect, in so far that I do not propose 

 to do more than state, as clearly as I can, what I believe 

 to be the special dominating condition that underlies the 

 evolution of the lepidopterous pupa, from its earliest to 

 its latest forms. It is obvious that if there be such a 

 condition, and it can be at all successfully appi"ehended, 

 it will give us much greater certainty in using the details 

 of pupal structuie as guides to the true phylogeny of the 

 Lepidoptera, and will show us in what respects they are 

 of value, and whei^e they give less definite indications. 



Though I cannot claim to present the subject in more 

 than a tentative form, I am emboldened to do so by the 

 encouragement given by our President in his last address 

 to the use of the " scientific imagination," of which I hope 

 this is a legitimate instance. 



What 1 have to advance may be stigmatised as a mere 

 speculative hypothesis. Perchance it may prove to be so 

 and nothing more. My own belief is that it will be 

 useful and valuable in guiding the study of pupal forms 

 and understanding their significance, even if it should 

 finally appear that it has a very secondary, instead of a 

 primary, place in marking out the lines of lepidopterous 

 evolution. 



The precise lines by which the quiescent, inactive 

 pupa, say of bees or beetles, was derived from the active 

 larva-like pupa, if the term is indeed at all applicable, 

 such as those of bugs or crickets, hardly concerns me 

 here ; but it is of interest to note that the great mass of 

 Goleoptera and Hymenoptera have a pupa of very uniform 

 type, helpless from its quiescence, and hence resorting 

 for protection to some cocoon or other cavity. Probably 

 as secondary to such protection, being of very delicate 



TRANS. KNT. SOC. LOND. 1896. PART IV. fDEC.) 



