/}< 



ucca Moths. 



97 



spine, but the barest trace of dorsal spines on the abdominal 

 joints. It issues partly from the stem in giving out the moth. 

 As I have elsewhere remarked: 



'' Who, studying these two species in all their characters and 

 hearing, can fail to conclude that, notwithstanding the essential 

 differences that distinguish them not only specifically, but ge- 

 nerically, they are derived from one and the same ancestral form ? 

 Pronuba, depending for its existence upon the pollination of the 

 flower, is profoundly modified in the female sex in adaptation 

 to the peculiar function of pollination. Prodoxus, dwelling in 

 the flesh of the fruit or in the flower-stem and only indirectly 



Fro. 12. PKODOXCS DKCIPIKXS: a, larva ; l>, head from above ; c, d, left jaw and antenna ; 

 e, pupa: /, infested stem cut open to show thn burrows, eastings, ooeoons, and pupa 

 shell (/t)-all enlarged but f, the hair-line between a and c showing natural length. 



depending upon the fructification of the plant, is not so modified, 

 but has the ordinary characters of the family in both sexes. In 

 the former the larva quits the capsules and burrows in the 

 ground ; it has legs to aid in its work, while the chrysalis is 

 likewise beautifully modified to adapt it to prying through the 

 ground and mounting to the surface. The latter, on the con- 

 trary never quitting the stem has, no legs in the larva state- 

 and in the chrysalis state is more particularly adapted, by the 



i:i Him.. Sor.. WASH.. Ym.. VII, 1S!> 



