the secondary sexual characters and the Gonads. 339 



and glandulae accessoriae, but also in the presence of one 

 or two ovaries, one or two cement-glands and the sper- 

 matheca. Similarly the secondary sexual characters of 

 the female may be normally and fully developed in the 

 absence of ovaries, cement-glands and spermatheca and 

 in the presence of the gonads and accessory glands of the 

 male. Thus the presence of gonads and glands of the one 

 sex has no modifying influence on the secondary sexual 

 characters of the other sex, even in the absence of the 

 gonads and glands proper to it. In some cases where 

 gonads and accessory glands of both sexes are present the 

 secondary sexual characters of both sexes are also present — 

 male characters on the side of the male organs and female 

 on the side of the female organs. The gynandromorph 

 Amorpha hybridus described in the preceding paper also 

 proves that secondary sexual characters of both sexes 

 may be present, male on one side, female on the other, 

 though neither testis nor ovary be present. Indeed, in 

 this case the accessory glands of both sexes were also 

 absent with the exception of a distorted cement-gland. 



The ducts, vasa deferentia, vesiculae seminales, and 

 ductus ejaculatorius in the male, oviducts, vagina, bursa 

 copulatrix and cervix in the female, can also be com- 

 pletely absent without affecting the development of the 

 secondary sexual characters, so that it is evident that 

 their epithelium produces no secretion which influences 

 the development of the secondary sexual characters. 



In the peculiar gynandromorphous Agriades coridon var. 

 roystonensis, of which I have published descriptions in the 

 Journal of Genetics and in these Transactions, scales of a 

 structure peculiar to the male were found usually on the 

 wings of one side only, yet no male internal organs were 

 present, and in most instances the female organs were 

 perfectly formed. The ovaries in all cases were of equal 

 size and fully developed. 



In some primary hybrid hawk-moths of the genus 

 Amorpha, of which a list has been published recently by 

 Dannenberg, and of which A. ocellatus <$ and A. populi $ 

 and A. ocellatus <$ x A. avstati $ are the best known, 

 females are replaced by insects in which the external 

 genitalia are roughly symmetrical, but show a mosaic of 

 male and female characters. The male and female parts 

 are for the most part fully formed, and are not inter- 

 mediate in characters between the two sexes. Ill-formed 



