THE TESTICLE AND THE OVARY 341 



reeords instances of a hen chaffinch with male plumage and an unlaid 

 egg, a hen redstart with male plumage and a number of developing 

 eggs, as well as similar cases of hen pheasants. The male plumage 

 may be only temporarily assumed. Further examples of the 

 assumption of male plumage by hen birds are recorded by Shattock 

 and Seligmann,^ who describe the phenomenon under the name of 

 allopterotism. Some of these cases are regarded as of the nature 

 of partial hermaphroditism. It would appear possible that the 

 secondary male characters are normally latent in the female, and that 

 the ovaries exert an inhibitory influence over their development. On 

 the other hand, there is no clear evidence that castration in the male 

 animal leads to the assumption of female characters, excepting in a 

 negative sense (i.e. excepting in so far as it inhibits the development 

 of male characters). 



The operation of complete ovariotomy is difficult in birds owing 

 to the diffuse condition of the ovary and the close proximity of the 

 vena cava, and in de-sexing pullets (or converting them into 

 " poullardes ") the usual practice is to remove a portion of the oviduct 

 or destroy in some other way its functional relation with the ovary .^ 

 This operation is believed to favour growth and fattening, but the 

 result may be due simply to the fact that the albumen and the other 

 products of oviducal secretion are no longer produced. 



According to Brandt,^ the absence of a functional oviduct may be 

 correlated with male characters and a normal ovary, this being stated 

 to be the case in a specimen of JRuticilla phmnicurus, but such- a fact 

 seems on the face of it unlikely excepting on the assumption that a 

 partial hermaphroditism existed. 



Goodale * was the first completely to remove the ovary from a bird, 

 and by employing brown Leghorn fowls in which sexual differentiation 

 is very marked he obtained very clear results. It was only in young 

 birds that the ovary was sufficiently compact to make the operation 

 practicable. In the successful experiments the hen assumed the full 

 plumage of the Leghorn cock, with red back, black breast, and long 

 pointed hackle and saddle feathers. Spurs also developed. The 

 comb and wattles developed irregularly. The birds did not crow. 



1 Shattock and Seligmann, " An Example of True Hermaphroditism in the 

 Common Fowl, with Eemarks on the Phenomena of Allopterotism," TraTis. 

 Faih: Soc, vol. Ivii., 1906. "An Example of Incomplete Glandular Hermaphro- 

 ditism in the Domestic Fowl," Proc. Roy. Soc. Med., Path. Section, vol. i., 

 (November) 1907. __ ^ , .^ 



2 Wright, The New Book of Povltry, London, _ 1902. Laycoek, Nervous 

 Diseases 0/ Women, London, 1840. 



3 Brandt, " Anatomisches und Allgemeines uber die sogenannte Hahnen- 

 fedrigkeit und iiber anderweitige Gesehlechtsanomalien bei Vogeln," Zeitsch. 

 f. wiss. Zool., vol. xlviii., 1899. This paper also cites numerous cases of hen 

 birds assuming male plumage, and many references are given. 



* Goodale, Oonadectomy, etc., Carnegie Inst. (Washington) Pub., 1916. 



