BIOCHEMISTRY OF THE SEXUAL ORGANS 311 



The observations of Miescher l allowed of a quantitative estimation 

 of the amount of nucleic acid and protamine present in the head of 

 the spermatozoa of the salmon after the fat had been removed. 60'5 

 per cent, of nucleic acid was found to be combined with 35'5 per cent, 

 of salmine, so that 96 per cent, of the head of the spermatozoon 

 consists of protamine nucleate. This protamine nucleate is, however, 

 not of the same nature in different parts of the head, the outer layer 

 containing a basic nucleate rich in protamine, while the inner portion 

 is composed of an acid nucleate poorer in protamine. 



The same quantitative relations have been shown to exist in the 

 spermatozoa of the herring, 2 and similar conditions may be assumed 

 to exist in the case of the spermatozoa of other animals, the only 

 difference being the nature of the protein molecule which is combined 

 with the nucleic acid. It is a protamine or a histoiie in the case of 

 the fishes, but a typical protein in the case of the higher Vertebrates. 3 



Of the remaining four per cent, about one-half consists of inorganic 

 salts, mainly calcium phosphate and calcium carbonate, while the 

 other half consists of an organic substance, the composition of which 

 has not yet been recognised. The most important fact known about 

 it is that it contains 0*12 per cent, iron in organic combination. 

 The presence of iron can be recognised only after incineration. To 

 this iron - containing organic substance Burrian 4 applies the name 

 " Karyogen," a word originally coined by Miescher to designate the 

 residue which he obtained after what Schmiedeberg's 5 calculations 

 showed to be an incomplete extraction of the protamine and nucleic 

 acid from the heads of the spermatozoa of the salmon. Since 

 Macallum 6 was able to demonstrate by means of a microchemical 

 method the presence of iron in the chromatin of the nuclei of cells, 

 it seems possible that the " Karyogen " represents the chromatin 

 substance of the spermatozoon. 



The chemical analysis of the spermatozoon is therefore complete. 

 It shows that the tail is very rich in. phosphorised fats which are 

 accompanied by cholesterin, fats, and a typical protein. The head 

 consists almost entirely (ninety-six per cent.) of a substance a 



1 Miescher, hutochemischc Arbeiten. 



2 Bendixand Elstein, "Uberden Pentosengehalt tierischer und menschlicher 

 Organe," Zeitsch.f. allgcm. Physiologic, vol. ii., 1902. 



3 Mathews, "Zur Chemie der Spermatozoon," Zeitsch. f. physiol. Chem., 

 vol. xxiii., 1897. 



4 Burrian, Ergebnisse der Physiologic, vol. v., 1906. 



5 Miescher, " Physiologisch-chemische Untersuchungen iiber die Lachsmilch, 

 nach den hinterlassenen Aufzeichnungen u. Versuchsprotokollen des Autors 

 bearbeitet u. herausgegeben von O. Schmiedeberg," Arch. f. experiinentclle 

 Pathologic u. Pharmakologie, vol. xxxvii., 1896, and in Histochcmische v.. Physio- 

 logische Arbeiten von Miescher. 



6 Macallum, " On the Demonstration of the Presence of Iron in Chromatin 

 by Microchemical Methods," Proc. Roy. Soc., vol. 1., 1892. 



