BIOCHEMISTRY OF THE SEXUAL ORGANS 299 



These facts suggest that this special arrangement of alternating 

 C and N atoms is the chemical expression of the specific function 

 of the nucleus, and that this arrangement plays a special part 

 in bringing about the chemical processes which lead to growth 

 and to the new formation of hvirig matter. 



In the case of the other organic compound present in every 

 nucleus, which contains iron in organic combination, the 

 evidence that it plays an active part in the synthetic functions 

 of the nucleus is even more suggestive. It was shown by 

 Spitzer ^ that the oxidising enzymes which are present in every 

 cell are locahsed in the iron -containing constituent of the 

 nucleus, and Loeb concludes that the nucleus must be regarded 

 as the essential respiratory or oxidising organ of the cell.^ 

 Oxidation processes are generally supposed to be necessary 

 only for the transformation of chemical energy into heat 

 and mechanical work. But they are, according to Loeb, equally 

 necessary for other more important and more general vital 

 processes, i.e. growth and cell division, which come to a stand- 

 still in the absence of oxygen. As a rule, cell division foUows 

 upon the formation of nuclear material, especially chromatin 

 material, from the protoplasm of the cell. If we accept 

 Schmiedeberg's ^ view that in the hving cell synthetic processes 

 may occur through the intervention of oxygen, we may conclude 

 that the oxygen which is required for the process of cell division 

 is probably needed for the synthesis of this nuclear material, 

 and, since the iron-containing organic compound present in the 

 nucleus has the power of bringing about oxidations, it would 

 follow that the synthetic functions of the nucleus are dependent 

 upon this compound. It must, however, be understood that 

 these considerations are still very hypothetical, and that other 

 biologists ■* deny that the nucleus is the respiratory or oxidising 

 centre of the cell. 



The power possessed by the spermatozoon of bringing about 

 segmentation of the ovum has been attributed by some authors 



* Spitzer, ' ' Die Bedeutung gewisser Nukleoproteide fur die oxy dative 

 Leistung der Zelle," Pfliiger'a Archiv, vol. Ixvii., 1897. 



^ Loeb, Dynamics of Living Matter, New York, 1906. 

 ' Sohmiedeberg, " Uber Oxydationen und Synthesen im Thierkorper," 

 Archiv f. experimentelle Pathologic u. Pharmakologie, vol. xiv., 1881. 



* See Verworn, Allgemeine Physiologic, 1909. 



