332 THE PHYSIOLOGY OF REPRODUCTION 



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

 M tli- two 411 ill-shaped horny spikes which are found normally 

 in the intn.niittent sac of the male (see p. 258). Sand, 1 too, has 

 deM-rilied hypertrophy of the clitoris in the masculinised rat. -The 

 latter author l::is carried out a series of experiments upon the 

 ligaturing and section of the vas deferens and upon artificially 

 produced cryj>t<>rchism (or the condition in which the testis is 

 retained in the hody 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 

 M>ore, 2 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 

 spennatogenic 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."-' 1 Since the retained or cryptorchkl testicle comes 

 tn mnsist mainly or entirely of interstitial tissue we hatfe here 

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

 secretion. 4 Lipschut//' has shown that in the guinea-pig after partial 

 castration a portion of testicular tissue one-sixteenth the normal 

 M/e 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. 



Shattoek and Seligmann (1 have described the results of occluding 



1 Sand, '' Kxpcriments on the Internal Secretion of the Sexual Glands, 



i-|..ri;illy <>n Experimental Hrnnaphroditism," .Inn,: of /'/it/xiot., vol. liii., 1919 ; 



<m> i.t'llf St,i< //.-/ ooer A>//x/w/w/7<vv/' AM /'atfi-dt/r, Copenhagen, 1918; 



" Ktudes Kxperimentales, etc.," I., II., and III., Join: 'de /'////.<. />/ /'at/,, d'e'/i., 



l'.iM and \'.t-2 



- MiMii-e (A.), "On tin- Physiological Properties of the (Jonads, etc.," Jour, of 

 / '.. vis. \\\iii. and xxxiii., 1919 and 1921. 



3 Corner, />M,.,M,-X ,,f tl, Mnl,' <;.,,,;,; Ur ; i<iux, Oxford, 1907. See also 

 M. Adam K.-.-lcs, Tl,,- [mparfetly I ),*,;, !>,! Tatu, Fx>ndon, 1903. 



4 For fuithei' information and references see liiedl, Tl,'- Internal ,SVv/Wo/-// 



Mulish Translation, Ix>ndon, 1!)17. 



' Lradrata, -Sui- l.-s Consci[ii'nccs de la Castiution jiartielle," C. ll.dela 

 A'/"/., vol. Ixxxiii., l!^o. 



- Sh;itt-"-k and Si-li<fniann, "Observations upon the Ac-(|uireinent of 

 Seeonoan S.-\ual Characters, indicating the Formation of an Internal Secretion 

 bv the Testid.-. /' - /,'_,/. ,v,,,., vol. Ixxiii., 1904. The same investigators 

 aloattemj)t.-<l t.. ol.tain further evidence by grafting together two cocks, one 

 astrate<l and the other normal, but these experiments were unfortunately a 

 failure, one of the birds alwavs dving after a short time. (Tram. Path Soc 

 vol. xlvi., 1905.) 



