The Origin of the Markings of Caterpillars. 1 7 1 



find that not only did their adult larvae agree in 

 every detail of marking, but also that the entire 

 phyletic development of these markings, as re- 

 vealed by the ontogeny of the larvae, had taken 

 precisely the same course in both species, we 

 should certainly conclude that they possessed a 

 near blood-relationship, and should place them 

 close together in the same genus. Such an in- 

 stance is afforded by the two Hawk-moths, Chcero- 

 campa Elpenor and C. Porcellus, as will appear in 

 the course of these investigations. These two 

 species were placed by Walker in different genera, 

 the form relationship of the 1 imagines being thus 

 correctly represented, since Porcellus (imago), is 

 indeed more nearly related in form to the species 

 of the genus Pergesa, Walker, than to those of the 

 genus C/uerocamfat Nevertheless, these species 

 must remain in the same genus, as no other ar- 

 rangement expresses their degree of blood- 

 relationship. 



An intimate knowledge of the development- 

 stages of caterpillars thus offers, even from a sys- 

 tematic point of view, an invaluable means of 

 judging the degree of blood-relationship, and from 

 this standpoint we must regard the study of the 

 caterpillar as of more importance than that of the 

 perfect insect. Certainly all groups would not be 



4 [In his recent revision of the Sphingidce, Mr. A. G. Butler 

 (Trans. Zoo. Soc., vol. ix. part x.) retains Walker's arrange- 

 ment. R.M.] 



