BIOCHEMISTRY OF THE SEXUAL ORGANS 289 



protamine, and a substance rich in phosphorus, having the 

 nature of an acid and belonging to the group of substances 

 known as nucleinic acids, which occur in the nuclei of somatic 

 cells in combination with protein substances as the so-callecL 

 nucleoproteins. 



The comparative chemical investigations of Kossel showed, 

 that while the nucleinic acid radicle present in the spermatozoa 

 of various species of fishes shows only very little variation, 

 the basic part is different for each species. It has, therefore, 

 been found convenient to distinguish these basic substances 

 by separate names, derived from the Latin names of the species 

 of the fish in which they occur. The basic substance of the 

 head of the spermatozoon of the salmon is salmine, that of the 

 herring clupeine, and so on. Since they have certain general 

 chemical and physical characters in common they have been 

 classed together in a group, which has received the name " Pro- 

 tamine/' which was originally used by Miescher to denote the 

 basic substance in the spermatozoa of the salmon. 



The protamines are strongly basic substances which absorb 

 carbonic acid from the air. They are soluble in water, insoluble 

 in alcohol and ether ; not coagulable by heat ; free from sulphur. 

 They are very rich in nitrogen, the percentage amount varying 

 from 33 per cent, to 25 per cent., while that of an albumen or 

 globulin is about 16 per cent. They give a strong biuret re- 

 action. Like other proteins, they are precipitated by tannic 

 acid, phosphotungstic acid, picric acid, and ferrocyanic acid ; 

 but while the proteins are precipitated by these reagents in acid 

 solution only, the protamines, by virtue of their basic character, 

 form a precipitate with these reagents even in alkaline solution. 

 They form compounds with the salts of the heavy metals (copper, 

 mercury, silver, platinum). The protamines combine with many 

 other protein substances in neutral or faintly alkaline solution, 

 so that a precipitate is formed if, for example, a solution 

 of protamine is added to a solution of caseinogen. 1 



If injected into an animal they have a strongly toxic action, 

 even if small doses are given. 2 



1 Hunter (A.), " (Jber die Verbindungen der Protamine mit anderen 

 Eiweiss-korpern," Zeitschrift f. phys. Chemie, vol. liii. 1907. 



2 Thompson, " Die physiologische Wirkung der Protamine," Zeitschrift f. 

 physiol. Chemie, vol. xxix., 1899. 



T 



