144 



ENTOMOLOGY 



FIG. 184. 



crustaceans, 2 spiders, 2 Orthoptera, 8 Diptera, 9 Coleoptera, 

 51 Hymenoptera and 255 Lepidoptera. The large proportion 



of Lepidoptera is due in great measure 

 to the fact that they are collected 

 oftener than other insects (excepting 

 possibly Coleoptera) and that sexual 

 dimorphism is so prevalent in the 

 order that hermaphrodites are easily 

 recognized. 



The most common kind of her- 

 maphroditism is that in which one 

 side is male and the other female, as in 

 Fig. 185. Bertkau found this right- 

 and-left hermaphroditism in 153 in- 

 dividuals. In other instances the 

 antero-posterior kind may occur, as 



Ovum of a butterfly, Va- 

 nessa, in its foiiicie. e, foi- when the fore wings are of one sex 



licle epithelium; g, germinal 

 vesicle; n, branching nucleus 

 of nutritive cell; o, ovum. 

 After WOODWORTH. 



FIG. 185. 



and the hind wings of the other ; 



rarely, the characters of the two sexes 



are intermingled. 

 Hermaphroditic insects are such rarities that very few of 

 them have been sacrificed to the dissecting needle in order to 

 determine whether the 

 phenomenon involves the 

 primary organs as well as 

 the secondary sexual char- 

 acters. Where dissections 

 have been made it has 

 been found usually that 

 hermaphroditism does ex- 

 tend to the reproductive 

 organs themselves. Thus 

 a butterfly with male 

 wings on the right side 

 and female wings on the 

 left would have a testis on the right side of the abdomen and an 

 ovary on the left side. 



Hermaphrodite gypsy moth, Porthetria dis- 

 par; right side, male; left, female. Natural 

 size. After TASCHENBERG, from Hertwig's 

 LehrbucJi. 



