30 



THE CATERPILLAR. 



FIG. 40. Clubbed spine of caterpil- 

 lar of Basilarchia Astyanax (a), X 3, 

 and of B. Archippus (6, c), X about 3. 



the warts have changed to very variable tuber- 

 cles, one set, mounted on the highest hunch, pre- 

 senting a formidable appearance as a pair of 



knotted clubs as long as 

 the breadth of the body 

 [Fig. 40]. In the angle- 

 wings (Praefecti), which 

 furnish the ordinary 

 spiny caterpillars, these 

 spines are compound in 

 the adult (that is, they 

 bear subsidiary spin- 

 ules), and are arranged 

 in certain definite rows. In their earliest life, 

 these caterpillars are furnished with long taper- 

 ing hairs [Fig. 41] also arranged in definite series, 

 but not occupying the same position as the spines 

 of the mature caterpillar. Now in each genus of 

 spiny caterpillars the spines occupy a certain 

 fixed place, and by 

 means of this feature, 

 among others, we define 

 the genus. Here then 

 the young and old cat- 

 erpillars plainly differ 

 from each other in ge- 

 neric features. To a casual view the caterpillars 

 of our blue butterflies, our coppers and hair- 

 streaks, appear quite naked ; they are, however, 



a b c d e 



FIG. 41. Spines of caterpillar of 

 Vanessa cardni at different periods- 

 fifth stages; differently 



