BIOCHEMISTRY OF THE SEXUAL ORGANS 303 



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 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-called imcleoproteins. 



The comparative chemical investigations of Kossel proved that, 

 while the nucleinic acid radical 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 

 " Protamine," 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 

 carl >onic 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 .'53 per cent, to 25 per cent., while that of an albumen or 

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

 Like other proteins, they are precipitated by tannic acid, phospho- 

 tungstic 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 



Although differing in many respects from the protein substances, 



1 Hunter (A.), "IJber die Verbindungen der Protamine niit anderen Eiweiss- 

 korpern," Zeitsch. f. physiol. (Jhem., vol. liii., 1907. 



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

 physioL Chem., vol. xxix., 1899. 



