70 STKICTLY INCOG. 



pigment, and a bluish layer in the skin which acts like the 

 iridium glass so largely employed by Dr. Salviati, being 

 seen as straw-coloured with a transmitted light, but as- 

 suming a fault lilac tint against an opaque absorbent sur- 

 face. While sleeping the chameleon becomes almost white 

 in the shade, but if light falls upon him he slowly darkens 

 by an automatic process. The movements of the corpuscles 

 are governed by opposite nerves and muscles, which either 

 cause them to bury themselves under the true skin, or to 

 form an opaque ground behind the blue layer, or to spread 

 out in a ramifying mass on the outer surface, and so pro- 

 duce as desired almost any necessary shade of grey, green, 

 black, or yellow. It is an interesting fact that many 

 chrysalids undergo precisely similar changes of colour in 

 adaptation to the background against which they suspend 

 themselves, being grey on a grey surface, green on a green 

 one, and even half black and half red when hung up against 

 pieces of particoloured paper. 



Nothing could more beautifully prove the noble supe- 

 riority of the human intellect than the fact that while our 

 grouse are russet-brown to suit the bracken and heather, 

 and our caterpillars green to suit the lettuce and the cabbage 

 leaves, our British soldier should be wisely coated in brilliant 

 scarlet to form an effective mark for the rifles of an enemy. 

 Bed is the easiest of all colours at which to aim from a 

 great distance ; and its selection by authority for the 

 uniform of unfortunate Tommy Atkins reminds me of 

 nothing so much as Mr. McClelland's exquisite suggestion 

 that the peculiar brilliancy of the Indian river carps makes 

 them serve ' as a better mark for kingfishers, terns, and 

 other birds which are destined to keep the number of these 

 fishes in check.' The idea of Providence and the Horse 

 Guards conspiring to render any creature an easier target 

 for the attacks of enemies is worthy of the decadent school 



