^44 THE ENTOMOLOGIST*S RECORt). 



Colour of Lepidopterous Chrysalides. — M. Bordage, Director 

 of the Natural History Museum, He de la Reunion, gave the results of 

 some experiments, showing the relation of the colour of the chrysalids 

 of certain Lepidoptera to that of their environment. The species 

 experimented upon were Atclla jihalanta, I'liiplDca t/oitdotii, Danais 

 chri/sij)jn(s, I'ainlii) deinoleus and /'. ilisjiarilis. A. pludanUi has, 

 normally, two types of chrysalis (1) bright green, with silvery car- 

 mine-tipped tubercles, (2) silvery-white in ground colour. Metallic 

 and bright-soloured surfaces gave a preponderance of the silvery-white 

 forms, whilst dark-coloured surfaces gave green forms. In complete 

 darkness, almost black chrysalids were developed, destitute of brilliant 

 points, and from these dwarf imagines were reared. The experimenter 

 considered that the intensity of the light was the important factor. 

 The brilliant tubercles rendered even the green chrysalids conspicuous 

 on the foliage, and it was found that birds rejected them after a single 

 trial. E. i/oudotii has a chrysalis that may be (1) silvery, (2) greenish- 

 gold in colour. The colour of the place of attachment was found to 

 have no influence on the resultant colour, but gold surroundings gave 

 a preponderance of the greenish-gold form, and silver of the silvery- 

 white form. In darkness, brownish-black bands and spots were 

 developed on the silvery ground. This chrysalis is also rejected by birds. 

 P. chri/sipjnis has three types of chrysalis, (1) pale rose, (2) bright 

 green, (3) yellowish. The experimenter found, with Trimen, that 

 there is little sensitiveness to colour surroundings, though Morris came 

 to a different conclusion. Metallic surfaces, however, gave more green 

 forms, while dark surfaces — and especially complete darkness — in- 

 creased the number of the paler forms. The chrysalids of the two 

 Papilios showed no sensitiveness to the colour of their environment. 

 The contrary results obtained by some experimenters was assumed to 

 be probably accidental, their conclusions being based on very few 

 examples. These Papilios appear to have lost any sensibility to colour 

 that they may have at one time possessed. 



Mr. Roland Trimen considered that the paper of M. Bordage was of 

 great interest. Of the five specimens, three were of wide African 

 distribution, and two of them, Danais chn/sipjnis and Vapilio demulcm^ 

 he had himself experimented on at the Cape, and found that while 

 the Danain did not respond to artificially-prepared surroundings of 

 different colours, the Pajnlio did respond, to some extent, viz., when 

 the colours (shades of green and brown) more or less corresponded 

 with the surroundings found in the natural environment. P. bjaens, 

 a near relative of I', disjxnilis, of Reunion, had been shown by Mrs. 

 Barber of Grahamstown — who had bred a large number — to be highly 

 sensitive as a pupating larva, the pupa reproducing the green of leaves, 

 the brown of bark, the yellow of planed deal, and the red of brick. 



The morphological constitution of the imaginal insect head. — 

 M. Janet gave the results of his studies on the morphological structure 

 of the head of the ant. After having recapitulated the criteria, hitherto 

 employed to determine to which of the embryonic segments the 

 different parts of the integument of the imago correspond, he attempted 

 to show that a study of the musculature furnished an additional 

 criterion, confirming the results arrived at by other methods, and 

 filling up certain lacunfe which those methods had left void. After 

 some preliminary considerations, the object of which was to show that 



