PHYSIOLOGICAL RELATLONS OF NUCLEUS AND CYTOPLASM 341 



some interesting suggestions regarding the synthesis of complex 

 organic matters in the living cell with nuclein as a starting-point. 

 Chittenden, too, in a review of recent chemico-physiological dis- 

 coveries regarding the cell, concludes : " The cell-nucleus may be 

 looked upon as in some manner standing in close relation to those 

 processes which have to do with the formation of organic substances. 

 Whatever other functions it may possess, it evidently, through the 

 inherent qualities of the bodies entering into its composition, has a 

 controlling power over the metaboUc processes in the cell, modifying 

 and regulating the nutritional changes " ('94). 



These conclusions, in their turn, are in harmony with the hypothesis 

 advanced twenty years ago by Claude Bernard ('78), who maintained 

 that the cytoplasm is the seat of destructive metabolism, the nucleus 

 the organ of constructive metabolism and organic synthesis, and 

 insisted that the role of the nucleus in nutrition gives the key to its 

 significance as the organ of development, regeneration, and inheri- 

 tance.^ 



B. Physiological Relations of Nucleus and Cytoplasm 



How nearly the foregoing facts bear on the problem of the mor- 

 phological formative power of the cell is obvious ; and they have in a 

 measure anticipated certain conclusions regarding the role of nucleus 

 and cytoplasm, which we may now examine from a somewhat differ- 

 ent point of view. 



Briicke long ago drew a clear distinction between the chemical and 

 molecular composition of organic substances, on the one hand, and, 

 on the other hand, their definite grouping in the cell b\' which arises 

 organization in a morphological sense. Claude Bernard, in like man- 

 ner, distinguished between eheniical synthesis, through which organic 

 matters are formed, and morphological synthesis, by which the)' are 

 built into a specifically organized fabric ; but he insisted that these 

 two processes are but different phases or degrees of the same phe- 

 nomenon, and that both are expressions of the nuclear activity. We 

 have now to consider some of the evidence that the power of mor- 

 phological, as well as of chemical, synthesis centres in the nucleus, 

 and that this is therefore to be regarded as the especial organ of 

 inheritance. This evidence is mainly derived from the comparison 

 of nucleated and non-nucleated masses of protoplasm ; from the form, 



1 " II semble done que la cellule qui a perdu son noyau soit sterilisee au point de vue de 

 la generation, c'est a dire de la synthese morphologique, et qu'elle le soit aussi au point de 

 vue de la synthese chimique, car elle cesse de produire des principes immediats, et ne peut 

 guere qu'oxyder et detruire ceux qui s'y etaient accumules par une elaliDiation anterieure du 

 noyau. II semble done que le noyau soit \& gernie de nutrition de la cellule : il attire autour 

 de lui et elabore les materiaux nutritifs " ('78, p. 523). 



