238 THE PHYSIOLOGY OF REPRODUCTION 



secretion possess full functional activity, and are capable of 

 fertilising ova successfully. 



Serralach and Pares l have adduced evidence indicating that 

 the prostate is an internally secreting gland which controls the 

 testicular functions, and regulates the process of ejaculation. 

 It is stated that if the prostate is removed spermatozoa are no 

 longer produced in the testis, and that the secretory activity 

 of the accessory genital glands ceases. These changes, however, 

 can be prevented by the administration of glycerine extracts 

 of prostate gland. The experiments were upon dogs. The 

 most obvious criticism of Serralach and Pares' view is that it is 

 unlikely, on phylogenetic grounds, that the functional activity 

 of the essential organ of reproduction should depend on the 

 presence of an accessory gland of comparatively recent evolu- 

 tionary development. On the other hand, it is arguable that the 

 prostate may originally have formed part of the testis, and sub- 

 sequently have become differentiated as a separate organ in the 

 course of phylogeny. Reference may be made in this con- 

 nection to the somewhat similar theory, which certain gynaeco- 

 logists have held, that the ovarian functions are dependent on 

 an internal secretion arising in the uterus, whereas the most 

 recent experimental evidence proves clearly that this is not the 

 case (see p. 345). 



Griffiths 2 has shown that the prostate glands in the hedgehog 

 and the mole undergo definite cyclical changes which are cor- 

 related with changes in the functional activity of the testes 

 (c/. p. 232). In the quiescent state the prostate is composed of 

 a few tubules lined by small, flattened, epithelial cells, which 

 are at this time incapable of producing a secretion. With the 

 approach of the breeding season the tubules grow much larger 

 and the epithelial cells become columnar. During rut the 

 prostate gland is a mass of tortuous tubules, and has grown to 

 many times the size of the quiescent organ. The tubules are 

 described as being filled with coagulated mucus, containing a 

 number of small round cells resembling leucocytes ; while the 

 epithelial cells are said to show numerous mucigenous granules, 



1 Serralach and Pares, " Quelques donnees sur la Physiologic de la Prostate 

 et du Testicule," C. R. de la Soc. BioL, vol. Ixiii., 1908. 



2 Griffiths, " Observations on the Function of the Prostate Gland in Man 

 and the Lower Animals," Jour, of Anat. and Phys., vol. xxiv., 1890. 



