( vii ) 



adaptation bad been acquired by tbe ngcncy of natural 

 selection, but even in tbese cases no experimental work had 

 as yet been carried out in a satisfactory manner. He (Prof. 

 Meldola) had suggested many years ago that the green colour 

 of caterpillars had been brought about in this way by the 

 action of natural selection ; the faculty of assimilating the 

 chlorophyll of the plant having been acquired under the 

 influence of this agency. This suggestion was converted into 

 an established fact by Mr. Poulton's observations, chlorophyll 

 in a modified form having been detected in the blood of leaf- 

 feeding larvaj (Proc. Roy. Soc, 1885, pp. 2G9-315). 



Mr. W. White remarked that he thought there was rarely 

 any direct relation between the colour of food and the larval 

 skin-coloration, although it was the case with most sub- 

 terranean and internal feeders, which were generally more or 

 less transparent. It was evident that different food-plants 

 did not produce the divergence in colour common amongst 

 the NoctiKc from the fact that the dimorphic brown and 

 green forms of the lladenidm larvse were to be met with 

 upon the same plant, as he had frequently noticed ; and 

 he had found extreme types in the case of both H. pisi 

 and Euplexia lucipara feeding upon the same fern-frond. 

 The case is similar with Mamestra brassiccs, and probably 

 all the other species subject to this variation. On the 

 other hand, as had already been pointed out by Prof. Meldola, 

 the colour of the' leaves as an environment had been con- 

 clusively proved by experiment to be productive of varia- 

 tion in colour. It would be remembered that Mr. Poulton 

 had tested this very point with Smerinthus larvte, and found 

 that those which were fed upon a species of sallow, having 

 a silvery underside to the leaves, which only was seen 

 by the larv^, — each leaf being folded and sewn, — became 

 unusually pale in consequence, while others from the same 

 stock, Avhich were subjected to the normal appearance of the 

 same leaves, remained of the more usual yellowish-green 

 colour, the pabulum being the same, of course, in both cases. 

 Mr. B. A. Bower exhibited a specimen of Parasia ncurop- 

 terella, Z., bred from heads of Centaur ea scabiusa, and said he 

 believed the species had not been previously bred. He also 



