113 ) 



IX. On tivo Gynandromorphous specimens of CIrrochroa 

 Aoris, Doubleday, an Indian species of NympJia- 

 lideous Butterflies. By J. 0. Westwood, M.A., 

 F.L.S., kc. 



[Read April 7th, 1880.] 



Plate II. 



The term Gynandromorphism was first applied by M. 

 Lacordaire to supersede in entomology that of Herma- 

 phroditism, the latter term being more strictly applicable 

 only to those animals in which the generative organs of 

 both sexes are normally included in the same individual, 

 but which, nevertheless, require the presence of a second 

 individual of the same species to effect the joint impregna- 

 tion of the two individuals. In insects, gynandromorphous 

 specimens, partaking abnormally of the character of both 

 sexes, are generally bilateral ; the sexual distinctive charac- 

 ters (which are for the most part in these instances the 

 secondary ones) of one sex being exhibited on one side of 

 the body and its organs, and the peculiarities of the oppo- 

 site sex being seen on the other half of the insect. Of this 

 bilateralism many instances have been recorded, and most 

 extensive collections can boast of the possession of one or 

 more of such "half-and-half" monsters. Here the gynan- 

 dromorphism may be termed complete, but specimens of far 

 greater rarity, in which the abnormality is ou\y partial (of 

 which no notice occurs in any of the hitherto published 

 introductions or general works on the science), are now 

 known ; and in my Thesaurus Entomologicus I collected 

 together a number of instances in which, whilst the body 

 of the insect appears to be unisexual, the partial sexual 

 divarication is confined entirely to the secondary sexual 

 characters, exhibited by one or more of the Avings only. 

 The peculiar import of this strange modification in a 

 physiological point of view is very difficult to be under- 

 stood, and from the great rarity of the individuals, and 

 their small size, we can hardly hope to obtain specimens 

 sufficient for the necessary examination of the characters 

 of the primary and internal sexual organs. 



TKANS. ENT. SOC. 1880.— PART II. (jUNE.) I 2 



