260 Studies in the Theory of Descent. 



are " at first entirely light yellowish-green, but 

 become greener after feeding on the fresh leaves ;" 

 the horn is also at first light green, and then 

 becomes " darker." The young larvae spin webs, 

 by which they fasten themselves to the leaves of 

 their food-plant (this, so far as I know, has not 

 been observed in any species of Sphingidce). 

 They moult four times, the border round the head 

 and the purple stripes appearing after the third 

 moult, these stripes " having previously been 

 entirely white." The ecdyses follow at intervals 

 of about six days, increasing to about ten days 

 after the fourth moult. 49 



From this short account we gather that in the 

 third stage the marking consists of seven oblique 

 white stripes, which acquire coloured edges in the 

 fourth stage, a fact which I have myself frequently 

 observed. On the most important point Klee- 

 mann's observations unfortunately give no infor- 

 mation the presence or absence of a subdorsal 

 line in the youngest stages. That he does not 

 mention this character, can in no way be considered 

 as a proof of its actual absence. I am rather 

 inclined to believe that it is present in the first, and 

 perhaps also in the second stage. There occur, 

 however, species of the genus Sphinx (sensu stric- 

 tiori) which possess a subdorsal line when young, 

 as I think may be certainly inferred from the fact 



" Rosel, loc. cit. vol. iii., p. 26, note. 



