332 THE PHYSIOLOGY OF REPRODUCTION 



testis, and found it to contain normal corpora cavernosa penis as well 

 as the two quill-shaped horny spikes which are found normally 

 in the intromittent sac of the male (see p. 258). Sand,^ too, has 

 described hypertrophy of the clitoris in the masculinised rat. The 

 latter author has carried out a series of experiments upon the 

 ligaturing and section of the vas deferens and upon artificially 

 produced cryptorchism (or the condition in which the testis is 

 retained in the body cavity, brought about by Sand by occluding the 

 inguinal canal). These experiments confirm the importance of the 

 interstitial or puberty gland. Experiments upon the transplantation 

 of the gonads and upon sex reversal have also been carried out by 

 Moore,^ and these, together with other experiments by Sand on the 

 same subject, are described below in the chapter on sex determination. 



It has often been stated that an imperfectly descended testicle 

 in man, notwithstanding the fact that it may be without any 

 spermatogenic function, is nevertheless of the greatest benefit to 

 its possessor in virtue of its influence over the metabolism. "The 

 secondary sexual characters are a far more exact measure of the 

 value of the testicular tissues than are the presence of spermatozoa 

 in the external secretion. It may almost be said that a man's male 

 plumage is in direct proportion to the weight or amount of testicular 

 tissue present."^ Since the retained or cryptorchid testicle comes 

 to consist mainly or entirely of interstitial tissue we have here 

 further evidence that this gland is the organ of the internal testicular 

 secretion.* Lipschutz ^ has shown that in the guinea-pig after partial 

 castration a portion of testicular tissue one-sixteenth the normal 

 size is sufficient to admit of the development of the secondary sexual 

 characters, and he ascribes this result to the functional activity of 

 the interstitial tissue. 



Shattock and Seligmann ^ have described the results of occluding 



' Sand, "Experiments on the Internal Secretion of the Sexual Glands, 

 especially on Experimental Hermaphroditism," Jowr. of Physiol., vol. liii., 1919 ; 

 Experimentelle StwMen over E(tmskarahterer hos Pattedyr, Copenhagen, ] 918 ; 

 "Etudes Experimentales, etc.," I., II., and III., Jour, de Phya. et Path. Gin., 

 1921 and 1922. 



2 Moore (A.), " On the Physiological Properties of the Gonads, etc.," Jour, of 

 Exp. Zool., vols, xxviii. and xxxiii., 1919 and 1921. 



^ Corner, Diseases of the Male Oenerati've Organs, Oxford, 1907. See also 

 McAdam Eccles, The Imperfectly Descended Testis, London, 1903. 



* For further information and references see Biedl, The Internal Secretory 

 Organs, English Translation, London, 1917. 



^ Lipschutz, " Sur les Consequences de la Castration partielle," C R. de la 

 Soc. de Biol., vol. Ixxxiii., 1920. 



^ Shattock and Seligmann, "Observations upon the Acquirement of ' 

 Secondary Sexual Characters, indicating the Formation of an Internal Secretion 

 by the Testicle," Proc. Roy. Soc, vol. Ixxiii., 1904. The same investigators 

 also attempted to obtain further evidence by grafting together two cocks, one 

 castrated and the other normal, but these experiments were unfortunately a 

 failure, one of the birds always dying after a short time. {Trans. Path. Soc, 

 vol. xlvi., 1905.) 



