SOCIETIES. 89 



number of specimens of Campoiiotiis coiiipressus, C. viicans^ CEcophila 

 smaragdiua, Sima rufo/iii^ra, Solenopsis geminata var. armaia, and other 

 species of ants, from Calcutta, to^^ether with certain species of Aphidce 

 kept by them for domestic purposes ; also certain of their enemies and 

 parasites. He also communicated a short paper on the subject, entitled 

 "Notes on certain species of Calcutta ants, and their habits of life." — 

 H. Goss, Hon, Sec. 



South London Entomological Society. — March 24th, 1892, — Mr. 

 Merrifield re-read his paper "On the effects of artificial temperature on 

 the colouring of Vanessa Jirticce and certain other species of Lepidop- 

 tera." Mr. Merrifield said that at the time he commenced his experi- 

 ments, in 1887, Mr. Edwards, in America, and Prof. Weismann, in 

 German}', had shown that the colouring and markings of some butter- 

 flies were affected by temperature in the pupal stage. Their experiments 

 had been on seasonally dimorphic species, and tended to show that 

 temperature so applied, only operated on the summer-pupating form, 

 causing it to assume, or make a near approach to, the winter-pupating 

 form, but that the winter-pupating form could not thus be made to as- 

 sume the other form. Weismann's explanation of this was that the 

 winter-pupating form was the older one, and that the application of cold 

 (and indeed of other agencies) to the sunmier pupa caused it to " throw 

 back " to the ancestral form. His (Mr. Merrifield's) experiments 

 showed results which, while by no means inconsistent with this theory, 

 indeed in some respects supporting it, showed something more, and 

 indicated a general effect of temperature upon the colouring of both 

 the seasonal forms of some dimorphic species, and of some single 

 brooded species. A distinction was to be drawn between the single 

 brooded and the seasonally dimorphic species, as to the way in which 

 temperature operated. In the seasonally dimorphic species, no doubt 

 each individual, when it came into separate existence, had an innate 

 tendency to lead one or other of the two lives, viz. : — either to feed up 

 (juickly, and come out as a perfect insect after a few months, or to feed 

 slowly, and come out after passing the winter in the pupal stage. But 

 either of these tendencies might be diverted into the opposite one by 

 certain external agencies, of which temperature was a principal, but not, 

 he believed,the only one. Considering that one of the differences be- 

 tween two seasonal forms was often that of size, it seemed clear that 

 the question which of the two destinations the individual should follow 

 must, in the main, be decided before the period of full growth was 

 reached, i.e. before the end of the larval period ; and therefore such of 

 the markings and colouring as were proper to either seasonal form ex- 

 clusively, would thus indirectly be affected by circumstances operating 

 during the larval, or even the oval stage, viz., by those circumstances 

 which decided to which of the two seasonal emergences the perfect 

 insect should belong; and the earlier experiments before adverted to, 

 showed that similar results might, to some extent, be obtained by ex- 

 ternal agencies in the pupal stage. But it had now also been estab- 

 lished that temperature applied in the pupal stage to either seasonal 

 form of some seasonally dimorphic species, and to some single- 

 brooded species, materially affected the colouring, and, in some species, 

 the markings ; the markings, ai)parently by long-continued exposure in 

 the early part of the pupal period to a very low temperature (such as 



