OF GENERATION. 317 



narrow, but more feminine, of a yellow grey, with dark brown anal 

 tuft ; superior wings whitish, on each side dissimilarly mixed with 

 brown ; the right posterior wing coloured chieHy as in the male, the 

 left as in the female. Ochs. 



Gastrophaga quercus. Two individuals: 1st, body and antennae 

 female, as well as the left wings, the right male ; 2nd, body and right 

 side female, the left male; both antennae brown, and pectinated. 

 Ochsenh. 



Gastrophaga castrensis, O. Male, but having all its parts tending 

 to the female form ; right a female, left a male antenna, also on the 

 left side distinct female wings, whereas the right are entirely male, only 

 somewhat larger than in male insects, and the colours brighter than in 

 the female. In the Royal Museum at Berlin. Rudolphi. 



If we now cast a critical glance at these instances of hermaphro- 

 dite structure we shall speedily recognise that all of them may be more 

 correctly brought into the class of monstrosities. True natural her- 

 maphroditism exhibits perfect female in conjunction with perfect male 

 organs, and the external appearance of the animal is neither male nor 

 female, but an intimate mixture of both, a really new form. But this 

 in insects is never the case. One sex here is developed at the expense of 

 the other, and the more equal their mutual development, the more 

 heterogeneous is the appearance of the individual in its two halves. 

 The perfectly equal development of both sexual organs may be sup- 

 posed only in those cases in which the one half appears entirely male 

 and the other wholly female ; in all other instances one sex will pre- 

 dominate, to which the other is merely associated. This was the cha- 

 racter of both those instances which were subjected to anatomical 

 inspection ; both were properly males, which, besides their testes, pos- 

 sessed an ovary. This is still more the case in the so-called imperfect 

 hermaphrodites, for in them the preponderance of one sex is evinced 

 externally. A question which still awaits an answer is which side is 

 in general male, the right or the left ? and why is this male, and the 

 other female ? That we may answer this question we must group the 

 observed instances, and we then Hnd that in by far the majority of the 

 true hermaphrodites (in fourteen of the cited instances) the right is 

 male and the left female, and that seldomer far the right side is found 

 to be females and the left male (in nine instances). Among the imper- 

 fect hermaphrodites, on the contrary, the majority (six) were female, 

 and the minority (five) male with female characters : we may here 



