E. A. Cockayne 115 



halved examples probably arise in the same way as the rare halved 

 gynandromoi-phs of other hybrids such as Standfuss' Saturnia pavonia ^ 

 X S. spini 5 and halved gynandromurphs of pure species. They are 

 very i-are indeed. 



The reverse hybrid, A.pujmli c^ x A. oceUatus $ , has only produced 

 four imagines. The eggs are fertile but the larva fails to escape from 

 the shell. Males and females are said to have resulted, and the one 

 I have seen is a male in appearance. 



Standfuss in his extensive exjDeriments with the genus Saturnia 

 (emperor moths) found that in primary hybrids gynandromorphs were 

 comparatively rare, 2 in 4000, perhaps as rare as in »S'. pavonia itself 

 but in secondary hybrids they were numerous. 



Satia-nia {pavonia </ xpyri ^) J' x S. pyri $ gave five gynandro- 

 morphs out of eight imagines, S. (pavmiia ^ xpyri ? ) </ x (S. pavonia % 

 gave 12 out of .54. Twenty liroods of secondary hybrids mixed together 

 gave 280 imagines with 27 gynaiidromorphous individuals. 



In external appearance almost all the secondary hybrid gynandro- 

 moi-phs were predominantly female and showed a coarse mosaic 

 arrangement, though in one or two a whole wing showed the secondary 

 sexual characters of one sex only. 



Unfortunately only those most like females were dissected and these 

 all contained ovaries, many with few and ill-formed eggs. None con- 

 tained testes or male sex cells in their ovaries. The external genitalia 

 showed the characters of both sexes. 



Harrison amongst several thousand primary hybrid Bistoninae found 

 only one gynandromorph. 



A second was bred by Mr Worsley-Wood. It is a specimen of 

 hybrid liarrisuni, Harrison, {Ithysia zonaria ^ x Lycia hirtaria $), 

 female in all respects except the left antenna which is male. But of 

 Harrison's secondary hybrids the ten imagines bred were all gynandro- 

 morphs, and 50 pupae were also without exception gynandromorphous. 

 Some of the imagines were predominantly male, others predominantly 

 female, but none showed any approach to a halved condition and none 

 examined were genetic hermaphrodites. The external structures showed 

 a coarse mosaic arrangement of male and female parts. {Vide Plates 

 in Oberthiir's Lepidopterologie Comparee.) 



8—2 



