The Origin of the Markings of Caterpillars. 199 



transference of these two primary ocelli to the other 

 segments. The eye-spots always originate on 

 segments four and five, and from these the trans- 

 ference mostly occurs backwards, although in 

 certain cases it takes place at the same time 

 forwards. Herein, i. e. in the origin of the eye- 

 spots, there lies a great distinction between the 

 genus Chczrocampa and the genus Deilephila, with 

 which it was formerly associated, and in which the 

 origin of a very similar kind of marking can be 

 traced to quite another source. 



THE GENUS DEILEPHILA, OCHSENHEIMER. 



I am acquainted with the caterpillars of nine 

 European and one North American species, 

 these differing in marking to such a wonderful 

 extent that they appear to offer at first sight but 

 little hope of being able to trace them to a common 

 form. These ten species can be separated, 

 according to their markings, into five groups, 

 which I will briefly define before entering upon 

 their ontogeny. 



The first group consists of three species, and 

 comprises the -commonest and most widely-ranging 

 of all the European species, Deilephila Euphorbia, 

 as well as D. Dahlii from Sardinia and Corsica, 

 and D. Niccea, a species of very restricted range, 

 which appears to occur only in one small district 

 on the French coast of the Mediterranean. These 



