THE ORIGIN OF GYNANDROMORPHS. 87 



characters to the type grossulariata are not known, nor the parentage 

 of the individual, no analysis of the case is possible. A third aberrant 

 type, nigra, has given a striking bilateral gynandromorph with gros- 

 sulariata (figured by Cockayne). The genetic evidence in regard to 

 this type obtained by Punnett fails to show that the character is a 

 simple Mendelian one, so that this evidence is not available for analysis. 



The most remarkable mosaics of male and female characters are 

 shown by hybrids of the gipsy moth, Porthetria dispar and japonica. 

 These mosaics have been described by several observers (Wiskott. 

 1897, Brake, 1907-1910; Brake and C.Frings, 1911 ; Goldschmidt; 1912- 

 1917; Poppelbaum, 1914). We owe to Goldschmidt not only a most 

 complete account of the hybrids between these two varieties, but of 

 hybrids involving several Japanese local varieties of this moth. In the 

 latter crosses a most astonishing series of mosaics come to light, not as 

 sporadic occurrences, but as regular phenomena of the cross. In his 

 earlier work Goldschmidt called these mosaic forms gynandromorphs, 

 but his later work shows, he thinks, that they are different from 

 gynandromorphs; he now calls them intersex forms. 



The normal males and females of the gipsy moth differ not only 

 in the characteristic sex differences of this group, but in other secondary 

 sexual differences also. The Japanese varieties show these same 

 sexual differences, though both sexes differ in color and in a few 

 minor points from the European species. Japonica female by dispar 

 male gives equal numbers of daughters and sons that are normal as 

 to sex, but the reciprocal cross, dispar female by japonica, gives 

 normal males and intersex females in equal numbers. 



These intersexual females from different crosses show a wide range 

 in structure, in color, and in behavior, from almost normal females 

 at one end of the series to forms that externally are about like the 

 normal male. Not only are the wings colored like those of the normal 

 male (with occasional flecks of white like the female), but the antennae, 

 the hair, the size, the genitalia, and the gonads themselves are mosaics 

 of male and female and intermediate conditions also. These relations 

 are more interesting where crosses involving different Japanese races 

 are compared. ^Vhen a race, Jap. G male is crossed to Jap. K female, 

 all Fi daughters are slightly intersexual. ^Vhen a race, Jap. H female 

 is crossed to Jap G male, the daughters are somewhat more like the 

 males, but the instincts are still female and they attract males. The 

 copulatory organs are so changed in the direction of the male that 

 mating is unsuccessful, and eggs can not be laid, although the char- 

 acteristic hairy sponges are made. WTien a race, Eur. F female is 

 mated to Jap. G male, the daughters are "more than half-way 

 between males and females." The secondary sexual characters are 

 almost male. The instincts and behavior are about intermediate 

 between those of the two normal races. Males are scarcely attracted 



