158 PHYSIOLOGY CHAP. 



from the histology of the testicle that in the lobules, besides 

 the convoluted seminiferous tubules which represent the chief 

 bulk of the tissue, there are found between the coils, characteristic 

 elements isolated or in groups which are called the interstitial 

 cells of the testicle. Besides being found in the interstitial con- 

 nective tissue of the tubules, these cells are also met with in 

 the fibrous septa, and in the more internal strata of the albuginea 

 (Figs. 41, 42). They are of considerable size (14-21 /j, in diameter). 

 The origin and nature of these interstitial elements is much 

 discussed, but it appears to us undeniable that they are epithelial 

 cells, and as such represent, as a whole, a true ductless gland or 

 organ for internal secretion, analogous to the thyroid and para- 

 thyroids, and, in respect to total size, certainly more conspicuous 

 than the last. According to the observations of Ancel and Bouin, 

 it appears very probable that the presumed internal secretion of 

 the testicle is formed by these elements, which have specific 

 characters, and have nothing to do with either the seminal cells 

 or the cells of Sertoli. 



BIBLIOGRAPHY 



The most complete monographs on the functions of the male genital apparatus 

 are the following : 



LEUCKART. Art. "Zeugung," Wagners Handworterbuch d. Physiol. iv., 1853. 



HENSEN. Physiol. d. Zeugung. Hermanns Handbuch d. Physiol. vi., 1881. 



S. EXNER. Physiol. d. miinnl. Geschlechtsfunkt. Handbuch d. Urologie, von 



Frisch u. Zuckerkandl, 1903. 

 NAGEL. Physiol. d. mannl. Geschlechtsorgane. Handbuch d. Physiol. d. 



Menschen, ii., 1907. 



On the sperm and the spermatozoa : 

 LODE. Arch. ges. Physiol. 1. 



CHROBACH. Wiener klin. Wochenschr. N. 51, 1901. 

 0. Lows. Sitzungsber. d. Wiener Ak ad. d. Wissensch. cxi., 1902. 

 VERWORN. Allgemeiue Physiol., 5. Aufl., 1909. 

 R. BURIAN. Ergebnisse d. Physiol. iii., 1904. 



On the functions of the Vesiculae Seminales and Prostate : 

 TARCHANOFF. Arch. ges. Physiol. xl., 1887. 

 GRIFFITHS. J. Anat. and Physiol. xxiv., 1890. 



OUDEMAN. Die accessorischcn Geschlechtsdriisen d. Saugetiere. Harlem, 1892. 

 STEINACH. Arch. ges. Physiol. Ivi., 1894. 

 STEINACH. Ibidem, 1894. 



REHFISCH. Deutsche med. Wochenschr. N. 16, 1896. 

 DISSELHORST. Die accessorischen Geschlechtsdriisen d. Wirbeltiere. Wiesbaden, 



1897. 



FURBRINGEK. Die Stbrungen d. Geschlechtsfuuktion d. Mamies. Wien, 1895. 

 WALKER. Arch. f. Anat. u. Physiol., 1899. 



POEHL. Die phys.-chem. Grundlage d. Spermintheorie. St. Petersburg, 1898. 

 CAMUS et GLEY. Compt. rend. Acad. science, Paris, cxxiii., 1896. Compt. rend. 



de laSoc. biol., 1897-1900. 

 STILLING. Arch. ges. Physiol. xcvi., 1903. 



On erection and ejaculation : 



ECKHARD. Beitr. z. Anat. u. Physiol. iii., Giessen, 1863. 

 LOVEN. Ber. d. sa'chs. Akad. d. Wissensch., 1866. 



