STATES OF INSECTS, 187 



species belonging to the same family are usually diffe- 

 rent; but in some cases the latter maybe prejudged from 

 the former. The larvae of many of the genus Sphinx L., 

 for example, have their sides marked by oblique streaks 

 running from the back in a direction towards the head ; 

 and by this last circumstance they are distinguished from 

 those of Bombyx xiersicolor, Attacus Tau, and others of 

 the same tribe, which have also lateral oblique striae, but 

 running from the back towards the tail a . The colours 

 of individual larvae of the same species are usually alike, 

 but in Sphinx Elpenor and some others they vary exceed- 

 ingly. Many, like those of Lasiocampa Rnbi, Saiurnia 

 minor, &c, are of one colour when first disclosed, and 

 assume others quite different in riper age. Just previ- 

 ously to changing their skin, the tints of most larvae be- 

 come as dull and obscure, as they are fresh and vivid when 

 the change has fully taken place ; and in some instances 

 the new skin is quite differently marked from the old one. 

 This is remarkably the case with the last skin of some of 

 the larvae of the genus Tenthredo L., which is entirely 

 different from all the preceding ones. As people when 

 they advance far in years usually become more simple in 

 their dress than when they were young, so the larvae in 

 question change an agreeably variegated skin for one of 

 a uniform and less brilliant colour b . Madame Merian 

 has observed with respect to Attacus Erythrince, that its 

 caterpillar is at first yellowish, with nine black striae 

 on each side: when arrived at one third of its size, 

 they become orange; the striae are obliterated, and in 

 their place a round black spot appears on each of the 



a lYien. Verz. 4. b Reauin. v. 92. 



