94 THE ORIGIN OF GYNANDROMORPHS. 



for me the history of the "species" question. The following note I 

 owe to him: 



"Papilio androgens is quite variable and, furthermore, shows sexual di- 

 chromatism. Three varieties are accepted: typical androgens (Colombia 

 to Trinidad, Guianas, Amazon, southward to Bolivia and western Matto 

 Grosso), epidarniis (Mexico to Panama, Cuba, Haiti, and Saint Lucia), and 

 laodocus (Brazil and Paraguay). The name polycaon has been used by 

 authors for each of these forms and has been applied to both males and 

 females. The name laodicns has usually (always?) been applied to the female. 

 It seems probable that the specimen in question was an ordinary gynandro- 

 morph of Papilio androgens laodicus." 



Cockayne has discussed at length the evidence showing that gynan- 

 dromorphism is commoner in certain species than in others, and 

 reached the conclusion that this is not due, in several cases at least, 

 to the more striking characters involved, but rather to some peculiar 

 defect in the sex-determining machinery of these species. Moreover, 

 there appears to be good evidence favoring the view that in certain 

 families the number of gynandromorphs is greater than in the race as 

 a whole. The cause of this "inheritance" is obscure. Possibly these 

 are cases of intersexuality rather than of true gynandromorphism. 



The evidence is more certain that gynandromorphs are more com- 

 mon in certain hybrid combinations than in the pure parent species 

 involved in the cross. Whether such combinations are generally due 

 to the greater liklihood of chromosomal elimination — a view that would 

 seem a priori possible — or to "partial fertilization" or to polyspermy 

 can only be determined when more definite material is obtained that 

 furnishes opportunity for genetic evidence. 



GYNANDROMORPHS IN OTHER INSECTS. 



The scarcity of gynandromorphs in other groups of insects is prob- 

 ably due in part to the absence of conspicuous differences between the 

 male and female in such groups as beetles or to certain groups being 

 less collected or observed than others. We have made no attempt 

 to search out in the literature all references to gynandromorphs. 

 Occasional references to gynandromorphs in earwigs, Orthoptera, 

 beetles, and bugs are to be found in the International Catalogue. 



GYNANDROMORPHS IN SPIDERS. 



In a recent paper J. E. Hull has brought together the few cases of 

 gynandromorphs in spiders that are known. The best example is 

 that described by Kulezynski that is male on one side and female on 

 the other. Another described by Falconer was also male on one side, 

 female on the other. Another gynandromorph described by the author 

 (Hull) is male and female anteriorly and female and male posteriorly 

 (quadripartite). Three other cases of bilateral gynandromorphs have 



