gQ [Septemtier, 



But tliis is only possible as long as the wings possess the appearance 

 of having been dipped into mucilage, an aj^pearanee which is well 

 known in young Odonata. 



The scales have just the same development as the wings. At 

 first they are little open sacs, communicating with the hollow of the 

 wing and the whole body, and at a later period are glued together 

 like the wings themselves. 



In the wangs and in the scales the hypodermal colors are formed 

 and finished before the wings stick together, and by this means they 

 are well preserved and safely encased. They have no more communi- 

 cation in the glued parts with the interior of the animal, and are 

 preserved in the same way, as if hermetically inclosed in a glass tube. 

 There are even here in the wings and scales many epidermal colors, 

 chiefly the metallic ones ; but all the brighter colors (for instance 

 the somew^hat transparent spots in the elytra of the Lanqyi/ridce, 

 Cicindelidce, &c., and m the greater number of Lepidopiera) are, a^ I 

 believe, hypodermal colors. 



Pinally, there sometimes occurs outside of the animal, that is, on 

 the epidermis, a kind of color which I consider as hypodermal color, 

 such as the pale blue on the abdomen of many Odonata, the white on 

 the outside of many Hemipfera, the jiale gray on the elytra and thorax 

 of the Goliathus beetle, the powder on Lixiis and others. Some of 

 these colors are very easily resolved in ether, and are apparently a 

 kind of wax. I believe that these colors are produced by the hypo- 

 dermis and are exuded through the little channels of the pores 

 ( Poren Cancdle) . 



The hypodermal colors are very often different in males and 

 females of the same species, the epidermal colors rarely differ so far 

 as I know ; but there are genera with prominent epidermal colors 

 which are nearly always different in different sexes, viz., Calopfen/x, 

 Lesfes, some Hymenoptera, &c. 



It would be interesting to know the different colors of the 

 epidermis in such cases. So far as I know the change seems to be 

 between related and not between complementary colors. But my 

 observations are far from having any conclusive importance. The 

 same investigation would be necessary for the hypodermal colors. 



The hypodermp.! colors may change or be altered in some way in 

 a male or female during its lifetime, by sexual or other influences. 

 The epidermal colors never change. By sexual influences yellow is 

 changed into orange, brown into red, and e^en sometimes more 

 clianged. By other influences, for iiistMiice liy cold in hibernation. 



