specific modifications of Japan Carahi. 517 



sunshine of the tropics, in places, that is, where it 

 would be most beneficial, such concealing absence of hue 

 is altogether lost. So before we can say this or that is a 

 protective colour, it must be proved that the cause of 

 colour in the animal is not the same as in the plant or 

 object it simulates. And should the animal be a larva, 

 which we believe is of more recent origin than a leaf, 

 we must show that the two, have not been together side 

 by side long enough, to acquire the same tints, by the 

 same processes. It might be said, but I think incor- 

 rectly, that blackness arises from the invigorating energy 

 derived from warmth, as blackness absorbs heat-rays, 

 but in that case it would not properly be a protective 

 colour, but an incident in another line of evolution. I 

 have noticed that Damaster, seeking for warmth, becomes 

 diurnal, and this, I think, is the natural course for an 

 insect to j)ursue. I think of blackness as a structure 

 formed by heat-rays, and that beetles are black because 

 from their habits of concealment they are not affected by 

 direct rays, nor by the air like Noctiue. 



This will help us to see why Carahi are black beneath, 

 for in their dry mountain habitat there is no upward 

 movement as in the tropics. On their upper surface 

 they are sculptured by the direct solar-ray, and their 

 body is the tegument of a nocturnal insect. Wherever 

 there is foliage there is also a certain amount of moisture, 

 and insects, such as Rhynchites betuleti, owe their colour 

 to it, and Carahidce, such as Colpodes and Lebia, of 

 arboreal habit, are not black beneath. Elaphrus also, 

 which inhabits a damp swamp, is wholly bright. I 

 must call to mind too, here, the fact, that two arboreal 

 species of Calosoma, scrutator and aurocinctum, found in 

 America, are brightly metallic above and beneath, and 

 that the body in sycophanta is wholly black, and I believe 

 the last is terrestrial. Geotrupes hypocrita, I think, is 

 bright beneath for the same reason that the Madagascar 

 Buprestidce are, for the fermentation going on in their 

 habitat gives an energy equivalent to the uprising 

 heat-rays of the jungle-forest. If a hand is held out 

 over decaying matter, warmth is felt, something like 

 that which strikes an open palm held out to the sun. 



The brightest colours which exist in Nature are those 

 which we see in insects and birds that are the most ex- 

 posed to the direct rays of the sun, and the brightest 

 and most metallic parts of those birds are those which 



