SEX STUDIES. XI 29 
VII. SUMMARY 
1. The eight hermaphrodite birds studied are females with 
embryonic or degenerating ovaries. 
2. Three of these birds were changing from a female to a male 
condition in respect to internal structure (gonads), external 
characters and sex behavior. 
3. There is no structural counterpart for the abnormal behavior 
of one hen treading another hen. 
4. The two guinea chicken hybrids studied had testes com- 
posed of undifferentiated tissue. This is a different condition 
from that found by Guyer in a guinea chicken hybrid, and there- 
fore calls in question Poll’s theory that the stage of germ cell 
development in hybrids depends on the closeness of the relation 
of the individuals crossed. 
5. Development of comb, spurs, and wattles does not stand 
in direct quantitative relation to the sex of the gonad. 
6. Body shape and carriage, have a general relation to the 
sex of the gonad. 
7. The interstitial cells clearly have no causal relation to the 
secondary sex characters in the abnormal birds here described. 
8. Amount of lutear cells or pigment is in precise correlation 
with the degree of external somatic femaleness exhibited by 
the individual. 
VIII. LITERATURE CITED 
Bonn, C. 8. 1914 Ona case of unilateral development of secondary male char- 
acters in a pheasant, with remarks on the influence of hormones in 
: ; production of secondary sex characters. Jour. Gen., vol. 3, p. 205. 
Branpt 1889 Anatomisches und Allgemeines iiber die sog. Hahnenfedrigkeit 
u. iiber anderweitige Geschlechtsanomalien bei Végeln. Zeitschr. f. 
wiss. Zool., Bd. 48, p. 101. 
EastTMAN, Outiver N. Letter in American Poultry Advocate, vol. -" p. 733. 
Goopate, H. D. 1916 Gonadectomy in relation to the secondary sex char- 
acters of some domestic birds. Carnegie Inst., Washington, Publ. 243. 
GupERNATSCH, J. F. 1911 Hermaphroditismu; verus in man. Am. Jour. 
ANAh Vole ls Dp. 267. 
Guyer, M. F. 1912 Modifications in the testes of hybrids from the guinea 
and the common fowl Jour. Morph., vol. 23, p. 45. 
Lituiz, F. R. 1908 Development of the chick. Holt & Co., N. Y. 
PEARL AND Curtis 1909 A case of incomplete hermaphroditism. Biol. Bull., 
VOle U7 peoiele 
