292 THE PHYSIOLOGY OF REPRODUCTION 



thymus, &c., and which form another class of the protein sub- 

 stances, to which the name histone has been given. In their 

 properties and their composition these substances, therefore, 

 take a place between the typical proteins and the protamines. 



The substance isolated from the spermatozoa of the carp, 

 cyprinine (or rather the two cyprinines, since two slightly 

 different substances have been isolated), is on the border-line 

 between the protamines and the histones. The cyprinines do 

 not contain any cystine, they are not precipitated by ammonia, 

 and only about 35 per cent, of their total nitrogen is present 

 in the form of diamino acids, mainly as lysine in the one of the 

 two cyprinines. 1 



The chemical differences which exist between the spermatozoa 

 of the different species and orders do not show any connection 

 with the zoological relationship. 



The significance of the presence of histones in the spermatozoa 

 of some fishes becomes more apparent if the development of the 

 sexual organs is considered. 



It was Miescher who pointed out that in the salmon the 

 sexual organs develop at the expense of the muscular system 

 and that the salmine deposited in the testis during the breeding 

 season must be derived from the proteins of the muscle, since 

 the fish does not take any food during that period. A com- 

 parison between the amount of arginine present in salmine, 

 and that present in the muscle of the salmon shows 2 that all 

 the arginine deposited as salmine during the breeding season 

 can be accounted for by the arginine which becomes available 

 by the involution of the muscular elements. 



This result would suggest that the formation of salmine is 

 not due to a profound chemical alteration of the various con- 

 stituents of the muscle-proteins, transforming the divers sub- 

 stances into arginine, but rather to a gradual enrichment in 

 arginine of the muscle protein by the splitting off of a number 

 of the other constituent substances. 



1 Kossel and Dakin, " Beitrag zum System der einfachsten Eiweisskorper," 

 Zeitechrifl f. phya. Chemie, vol. xl., 1904. 



2 Kossel, " Einige Bemerkungen iiber die Bildung der Protamine im 

 Thierkorper," Zeitachrift fur physiologische Chemie, vol. xliv., 1905. Weiss, 

 " Untersuchungen iiber die Bildung des Lachs-Protamins," Zeitschrift fiir 

 phyaiologische Chemie, vol. Hi., 1907. 



