392 INTERNAL SECRETIONS 



male body shape and carriage ; these birds never laid eggs, and 

 were indifferent as to sexual behaviour. They showed under- 

 developed ovaries; only one possessed both an ovary and a 

 testis which contained spermatozoa. The authors conclude 

 from their observations that the interstitial cells of the ovary 

 have nothing to do with the secondary sex characters, whereas 

 the amount of luteal cells or pigment is in precise correlation 

 with the degree of development of external female somatic 

 characters (p. 29). If the eight hermaphrodite birds are 

 arranged according to their degree of exhibited maleness in 

 regard to external male sex characters or sexual instincts, it 

 will be found that those which revealed more maleness had 

 gonads containing testicular tissue more or less developed. 

 But on the other hand the authors hold the opinion that the 

 "development of comb, spurs and wattles does not stand in 

 direct quantitative relation to the sex of the gonad," whereas 

 body shape and carriage have a general relation to the sex of 

 the gonad. 



Hartmann and Hamilton (1922) have described a new 

 case of true hermaphroditism in the fowl; the plumage was 

 a female one, spurs were present, and the head apparel was 

 developed as in a male. The sexual behaviour was an inter- 

 sexual one, the bird sometimes crowed like a cock and yet 

 clucked like a lajdng hen. It showed an interest in chickens, 

 but did not sit. It is stated that the bird had once laid an egg. 

 A testicle and an ovariotestis were found. In the ovarian 

 part interstitial and luteal cells were present. Spermatozoa 

 were found. 



Lately Crew (1923 c) has described a series of female birds 

 changing into males. In one case there was a complete 

 reversal from an egg-la3dng hen which raised many broods 

 to a functional cock which became the father of two chickens, 

 Fell (1923 b) has described the histological condition of the 

 gonads in Crew's cases. There was always development of 

 testicular tissue preceded by ovarian atrophy or disease. 

 Only in one out of eight cases were oocytes found. The mode 

 of formation of testicular tissue seemed to be almost identical 

 with the embryonic process, sex cords proliferating from the 

 peritoneum inwards into the ovary. There were great quanti- 

 ties of "luteal" cells. Fell is inclined to ascribe to these cells 

 female hormone-production, as they were not found in the 



