BOMBYCIDJE. 129 



the leading characteristics of both continents, i. e. 

 Africa and Asia ; a remark in which all who have 

 examined the insects of the two countries will not, 

 we think, hesitate to concur. * 



As far as we are acquainted with them, the cater- 

 pillars of this group are pretty similar to each other, 

 having smooth skins, generally of a yellow or green 

 colour, with transverse rows of tubercles of a diffe- 

 rent colour from the body. Considerable variations, 

 however, from this typical form, are observable in 

 many of the species. The caterpillar of A. ery- 

 thrince, for example, is even more anomalous than 

 the perfect insect, affording one of the most remark- 

 able instances with which we are acquainted of 

 important changes at different periods of develop- 

 ment. If we may place full confidence in the figures 

 which have been given of it, after having attained a 

 certain stage of its growth, it is either yellow spot- 

 ted with black, the head, legs, anal segment, and 

 caudal horn ferruginous; or it is black, with the 

 parts just mentioned ferruginous ; or, finally, it is 

 yellow with broad black rings. In all these modifi- 

 cations as to colour, it bears four very large black 

 spines behind the head, and two others near the 

 hinder extremity, t When full grown, all these 

 spines fall off with its last change of skin, and the 

 caterpillar is either black, yellow mottled with 



* Linn. Trans., vol. xviii. p. 437. 



"T In Madame Merian's figures, the size of the spines is 

 somewhat exaggerated. See the 11th plate of her Insects of 

 Surinam. 



