34 



Notes and Conwients. 



reference might be made to the experiments which have been 

 conducted for many years by Professor E. B. Poulton, F.R.S., 

 President of the Entomolog-ical Society of London. An instal- 

 ment of the Professor's work appears in the ' Transactions of 

 the Entomolog-ical Society for 1903 ' (Part 3), recently issued, 

 and is descriptive of his experiments upon the colour-relation 

 between lepidopterous larvae and their surrounding-s, and 

 especially the effect of lichen-covered bark upon Odontopera 

 hidentata, Gastropacha qiiercifolia, Amphidasis hehdaria, etc. 



COLOUR CHANGES BY ENVIRONMENT. 

 Professor Poulton's experiments were made with a view ta 

 ascertaining- what degTee of sensitiveness larvae possessed in 

 adapting- themselves to their food environments, for purposes, 

 of protection. They show that, althoug-h probably the great 

 majority of tree- and plant-feeding larvae are more or less 

 sensitive (some larvae are equally well protected by altogether 

 different methods), all species are not influenced by their sur- 

 roundings in the same degree, and even equally strongly 

 sensitive species are not always influenced in the same 

 way by similar surroundings. Odontopera hidentata and Amphi- 

 dasis hetularia, for instance, though forming some of the 

 best subjects for the experiments yet tried, differ considerably 

 in that respect, as it is found that the larvae of hidentata are- 

 much more sensitive to the imitation of lichens than to green 

 leaves, whereas in hetularia just the reverse is the case. These- 

 and numerous other important observations are to be found in 

 Professor Poulton's valuable paper, to which reference should 

 be made by all entomologists and students of evolution. 



OUR PLATE. 



The article referred to is illustrated by two excellent coloured 

 plates, one of which representing larvae of Odontopera hidentata, 

 we are able to reproduce, through the courtesy of the author 

 and the Council of the Entomological Society of London. 

 Plate IL, Figs. 6 and 7, represent half-grown larvae ; all 

 the others are nearly mature specimens. Fig. i shows the 

 effect of a larva of Odontopera hidentata on black-barked twigs 

 {Que reus cerris). Fig. 2 sliows the effect of an environment of 

 weathered, pale grey, barkless twigs. Fig. 3 shows the effect 

 of an environment of dark, purplish-brown, glossy twigs, 

 probably of birch. Fig. 4, larva on white-spotted, purplish- 

 Naturalist,, 



