THE ORIGIN OF GYNANDROMORPHS. 101 



Among the urodeles, la Valette St. George has described a newt 

 having external male characters and an ovotestis on each side. Among 

 the Anura several cases of hermaphroditism beside those referred to 

 above have been described. Loisel described a frog with the secondary 

 sexual characters of the male. On the right side no gonad was present 

 and on the left the ovary was small and pigmented. It had no ova. 

 This condition suggests that the male character had developed as a 

 result of natural castration, but on the other hand, the two conditions 

 may have had some common cause. Other cases of hermaphroditism 

 in frogs and toads are reported by Spengel, Knappe, Hoffman, and 

 Stephan. 



GYNANDROMORPHS IN REPTILES. 



Only two cases are known to me in this group — one a lizard and the 

 other a turtle. Jacquet has described an individual {Lacerta agilis) 

 that was externally a male, but had on each side a well-developed 

 oviduct that was attached to the cloaca at one end and opened into 

 the body-cavity at the other. No ovaries were present, however. 



Fantham has described a turtle (Testudo grceca) that had the 

 external characters of a male. The concavity of the plastron was 

 less marked than in a normal male. It had on the left side an ovo- 

 testis, and on the right a testis. Two ova were present in the former. 

 Such a condition might, as suggested above for the Crustacea, be 

 imagined to be due to chromosomal elimination, but the effect here 

 was not localized, but extended beyond the ovotestis, since both sets 

 of ducts were present. 



GYNANDROMORPHS IN BIRDS. 



The division into males and females is sharply drawn in the groups 

 of birds, although in some families, as in the pigeons, the external 

 differences (the secondary sexual differences) may be slight, while in 

 other groups, owing to the development of secondary sexual characters, 

 the external differences are very striking. In still other forms the 

 secondary sexual characters appear only at certain seasons of the 

 year and disappear largely at other seasons. The five cases of bilateral 

 gynandromorphs that have been recorded make the group of particular 

 interest in the present connection, while the exceptional conditions 

 shown by certain hybrid crosses of pheasants call for careful analysis, 

 especially in connection with what appears to be at least an analogous 

 condition in hybrids of the gipsy moth. 



The genetic evidence shows very explicitly that the female is hetero- 

 gametic, the male homogametic. The sex-linked inheritance shown 

 by poultry and canaries is strictly comparable to that in Drosophila, 

 except that in the birds the male has two Z chromosomes (or ZZ) and 

 the female one Z (and possibly also a W, i. e., she is ZW). The cyto- 



