THE ENTOMOLOGIST. 23 



Mr. T. VV. Wood exhibited a number of pupae of Papilio 

 Machaon, Pieris Brassica3 and P. Rapa3, exhibiting various 

 shades of colour corresponding with the colours of the sur- 

 faces to which they were attached ; and read the following 

 remarks on the coloration of chrysalides : — " All Lepi- 

 dopterists are probably aware of the very great variability 

 in the colouring of the chrysalides of butterflies, and I am 

 able to state, as the result of some years of observation, that 

 their colours are more or less derived from the objects in 

 their immediate vicinity. It is obvious that this assimilation 

 of their colours to their surroundings is of great use to them, 

 tending to their concealment and consequent immunity from 

 the attacks of enemies during their period of exposure in a 

 helpless state. The specimens of chrysalides on surfaces of 

 different colours which I now exhibit are, 1 trust, sufficient 

 to convince you of the truth of this statement. I find, as the 

 result of my experiments, that the skin of the chrysalis is 

 photographically sensitive for a few hours only after the 

 caterpillar's skin has been shed, and, as might be expected, 

 by putting the specimens in the sunshine at the time of 

 changing, and surrounding them as much as possible with 

 any desired colour, the npost successful results have been 

 obtained. Under these conditions the specific markings are 

 almost entirely overpowered if necessary to the assimilation 

 of colour ; and these markings are, in fact, entirely over- 

 powered in the exhibited green varieties of Papilio Machaon 

 and Pieris Rapae. I have not had an opportunity of seeing 

 the former species in its natural haunts, but the latter I have 

 observed, and have found the green variety of the chrysalis 

 on a green leaf, and on a door which was painted green (spe- 

 cimen shown). There are also before you green specimens 

 of Pieris Brassicae which were under a vine on the side of 

 a house which was of a stone-colour, with many others taken 

 from the adjoining side of the same house, where there was 

 no vine to affect their colour, but only the somewhat dirty 

 stone-coloured surface ; I particularly noticed that there 

 were no green specimens to be seen on this side, although 

 their number was very considerable, and they were attached 

 at various heights, some very near the ground, and others at 

 the house-top under the projecting eaves. Some of the 

 darkest specimens shown on blackened surfaces were exposed 



