92 THE ORIGIN OF GYNANDROMORPHS. 



From the elaborate list of gynandromorphs published in 1896 and 

 1897 by Schultz, and from the admirable resume by Cockayne in 1915, 

 the following cases have been chosen as the most instructive ones on 

 record. 



Wheeler (1915) describes a gynandromorph from a cross of Smerin- 

 thus ocellatus by Amorpha populi {hyhridus). The right side is female, 

 the left side male. 



"The left wings are pinkish, as in ocellatus, while the right wings are entirely 

 gray. The eye-spots of ocellatus are well developed on both wings, as is 

 also the red basal patch of populi. Right antennae like female populi, left 

 like male ocellatus. Right half of body light gray, left half brownish gray.' ' 



Since both sides of the body show some characters that belong 

 to both parents, it is highly probable that parts of both parental nuclei 

 are present on both sides of the gynandromorph. 



Briggs (1881) has also described a hybrid gynandromorph showing 

 the characters of Smerinthus ocellatus and populi — right side ocellatus, 

 ' left side populi. A figure is given, but no description. Whether from 

 the figure it would be possible to determine whether some characters of 

 both parents are present on both sides might no doubt be determined 

 by an expert, but the all too brief text gives no information. 



Harrison crossed Ennomos suhregnaria male by E. quercinaria 

 female, and obtained many hybrids that were "practically the mean of 

 the parents, except that they leaned in the color, both of the head and 

 body and possibly in the general structure of the warts and tubercles, 

 to the male parent." In describing one of these, Harrison says: 



"At first sight it is merely a male specimen with the left anterior female. 

 Dissection and close examination betray much more interesting characters 

 than that. The genitalia (fig. 4), although nearly so, are not quite purely 

 male ; the right lobe of the uncus is replaced by a fully developed right ovi- 

 positor or lobe, wliile the gathous on the same side is greatly disturbed, and 

 acts as if it were homologous to the female directing rods. In addition, 

 whilst the coloration of both sides of the body is male, the shape of the right 

 wing is female." 



Harrison points out that "whilst the majority of the characters of 

 the right side were female the color was wholly male." It appears 

 from this description that hybrid characteristics appeared throughout, 

 which indicates that other chromosomes than the sex chromosome 

 were involved on both sides; but since so small apart was distinctly 

 female, it is not entirely clear that the hybrid coloration affected this 

 part too. He states (as above) that "while the majority of characters 

 of the right side were female the color was wholly male.' ' Apparently 

 by male he means hybrid male coloration, and if so the case is 

 instructive. 



Harrison obtained another aberrant individual from this cross. He 

 states that "the right being exactly that of a normal hybrid, whilst 



