288 THE PHYSIOLOGY OF REPRODUCTION 



observations of Little John and Pirie l show that the substance 

 which forms the crystalline picrate is secreted by the prostate 

 and by Cowper's glands, and, further, that this substance appears 

 to be specific for human semen, since a negative result is ob- 

 tained with the semen of monkeys, rabbits, and rats. 



THE CHEMISTRY OF THE SPERMATOZOON 2 



Owing to the brilliant work of Miescher, 3 which has been 

 continued by Kossel 4 and his pupils, our knowledge of the 

 chemistry of the spermatozoon is more complete than that of 

 any other cell. 



Thanks to the intelligent generosity of the head of a large 

 fishery concern in Bale, Miescher obtained a liberal supply of 

 the milt of the salmon, the sexual organs of which develop 

 during the passage up the Rhine. By controlling his mechanical 

 manipulations by means of histological observations Miescher 

 was able to investigate separately the different morphological 

 elements of the spermatozoa. The tails of the spermatozoa are 

 very rich in phosphorised fats, and contain besides a typical 

 protein, cholesterin, and fat, in the following proportions : 



Proteins . . . . ". 41-90 per cent. 

 Phosphorised fats . . . 31-83 

 Cholesterin, fats . . . 26-27 



Similar conditions were found to exist in the case of other 

 fishes and in the case of the ox. The heads were found to 

 contain only traces of fat, lecithin and cholesterin, and to be 

 composed almost entirely of a substance very rich in phosphorus. 

 This on further investigation proved to be a combination of 

 a basic substance, very rich in nitrogen, which Miescher called 



1 Littlejohn and Pirie, " The Micro -Chemical Tests for Semen," Edin. 

 Med. Jour., 1908. (This paper contains references to the literature.) 



2 For a detailed account of this subject and the literature see Burrian, 

 " Chemie der Spermatozoen, I.," in Ergebnisse der Physiologic, vol. iii., 1804, 

 and "Chemie der Spermatozoen, II.," in Ergebnisse der Physiologic, vol. v., 

 1906. 



3 Miescher, Histochemische und Physiologische Arbeiten. Gesammelt und 

 Herausgegeben von Seinen Freunden, vol. ii., Leipzig, 1897. 



4 Kossel, " tiber die einfachsten Eiweisskorper," Biochemisches Centralblatt , 

 vol. v., 1906-7, Part I. 



