BIOCHEMISTRY OF THE SEXUAL ORGANS 301 



movements of spermatozoa are inactivated by acids. Novif spermatozoa 

 constantly give off COg and in doing so make the fluid in which they 

 are suspended sufficiently acid to inhibit their own movements. This 

 self-inhibition acts as a protective mechanism. Spermatozoa are 

 endowed with a definite store of energy, which since they are isolated 

 cannot be replenished. Their capacity for locomotion and their length 

 of life is therefore limited and depends on the rate with which they 

 expend their store of energy. But whether their life be long or 

 short, the total amount of energy which they can release as measured 

 by the total amount of CO^ which they excrete is constant.^ 

 They immobilise themselves in the testis and efferent ducts by means 

 of their own COg excretion and thiis save their energy until the 

 moment of ejaculation when the CO2 is absorbed by the prostatic 

 secretion. 



The secretion of the prostate also contains the substance which 

 gives the characteristic smell to the ejaculated semen, the lecithin- 

 like globules, and a proteru substance, which from its reactions 

 cannot easily be classified. The statement that this protein is an 

 albumose is probably not correct, since albumoses have never been 

 found to occur in a living cell. Camus and Gley^ found in the 

 prostatic secretion of some animals a ferment, vesiculase, which has 

 the property of coagulating the fluid in the vesiculfe seminales. The 

 presence of this ferment in the ejaculated semen produces the 

 formation of a coagulum. This ferment appears to have the function 

 of ensuring fertilisation, since it occurs only in those species where 

 the contact between male and female is of yery short duration 

 (see p. 248). Walker has shown, however (see above), that this 

 coagulating property is not exhibited by the secretion of the prostate 

 gland, but is found in the secretion of a separate glandular organ 

 which he terms the coagulating gland, and which is histologically 

 and functionally different from the prostate. 



Cowper's glands secrete a stringy mucinous substance. 



If a solution of iodine in potassium iodide is added to semen, 

 brown crystals are formed (Florence's reaction). This reaction is 

 common to many substances belonging to the group of organic 

 ammonium bases. One of the be^t-known members of this group 

 is choline, which forms part of the lecithin molecule, and is, therefore, 

 a constituent of almost every animal cell. Probably the reaction is 

 not due to spermine (see p. 299), as Florence * states, but to choline, 



1 Cohn, "Studies on the Physiology of Spermatozoa," Biol. Bull., vol. xxxiv., 

 1918. 



2 Camus and Gley, "Action Coagulante du Liquide Prostatique sui- le 

 Contenu des V^sicules Seminales," Compt. Retid., vol. cxxiii., 1896. 



* Florence, " Du Sperme et des Taches du Sperme," Archives d'Ant/iropologie 

 Criminale, vol. xi., 1896 ; vol. xii., 1897. 



