330 THE PHYSIOLOGY OF REPRODUCTION 



as a result of similar experiments, reached an identical conclusion. 

 Ancel and Bouin stated, further, 1 as a result of a series of experiments 

 upon guinea-pigs, that the subcutaneous injection of extract prepared 

 from the interstitial tissue of the testis prevented the effects which 

 castration otherwise would have produced upon the rest of the 

 generative system and upon the skeleton. 2 Their results, therefore, 

 differ from those of Walker. In another paper Bouin and Ancel 3 

 state that the injection of similarly prepared testicular extract in 

 guinea-pigs tends to promote growth. In the horse they found that 

 the development of the interstitial gland substance of the adult 

 coincided with the first occurrence of spermatogenesis ; but that 

 there was also a foetal interstitial gland, which disappeared at the 

 end of gestation, and a slightly developed gland composed of 

 xanthochrome cells, which was only found in the immature animal. 4 



Tandler and Gross 5 have described the effects of subjecting the 

 testes to the influence of the Eontgen rays. They found that in 

 the roebuck the spermatogenetic tissue is destroyed but the 

 interstitial tissue is unaffected, and in correlation with this the horns 

 develop as in the normal male. Leo Loeb 6 found that in guinea- 

 pigs with undescended testes the interstitial cells were present, and 

 although spermatogenesis 7 did not go on, sexual desire was manifested. 

 Secondary male characters, however, might be absent, the animal 

 showing female somatic characters (see p. 346). Whitehead 8 from a 

 study of abnormal testes likewise found that the sexual instinct was 

 associated with the existence of the interstitial cells. The present 

 writer 9 found as a result of an experimental investigation in the 

 hedgehog that the growth of the accessory organs (vesicuke, etc.) 



1 Bouin and Ancel, "Action de 1'Extrait de Glande interstitielle du Testicule 

 etc.," G. R. de VAcad. des Sciences, vol. cxlii., 1906. 



2 Castration in early life, as already mentioned, is said to lead to a prolonged 

 retention of the cartilaginous unions between the bones, especially in those of 

 the limbs. 



3 Bouin and Ancel, " Sur 1'Effet des Injections de 1'Extrait de la Glande inter- 

 stitielle du Testicule sur la Croissance," C. R. de la Soc. de Biol., vol. Ixi., 1906. 



4 Bouin and Ancel, "La Glande interstitielle du Testicule chez le Cheval," 

 Arch, de Zool. Kvper., vol. iii., 4th series, 1905. According to L6caillon the 

 interstitial tissue in the mole's testis is functionally active during the breeding 

 season, when the testis is sixty -four times larger than during the resting period. 

 ("Sur les Cellules interstitielles du Testicule de la Taupe consid6rees en dehors 

 de la P6riode de Reproduction," C. R. de la Soc. de Biol., vol. Ixvi., 1909.) 



5 Tandler and Gross, Die Biologischen Grundlagen der Sekundtiren Geschlechts- 

 charaktere, Berlin, 1913. 



6 Loeb, "Relations between the Interstitial Gland of the Testicle, Semini- 

 ferous Tubules and the Secondary Sexual Characters," Biol. Bull., 1918. 



7 See p. 164, Chapter V. 



8 Whitehead, "A Peculiar Case of Cryptorchism, etc.," Anat. Record, 

 vols. ii. and iii., 1908 and 1909. 



9 Marshall, " The Male Generative Cycle in the Hedgehog : with Experi- 

 ments on the Functional Correlation between the Essential and Accessory 

 Sexual Organs," Jour, of Physiol., vol. xliii., 1911. 



