334 CELL-CHEMISTRY AND CELL-PHYSIOLOGY 



phosphorus-free." ^ Further, " in the processes of vital activity there 

 are changing relations between the phosphorized constituents of the 

 nucleus, just as in all metabolic processes there is a continual inter- 

 change, some constituents being elaborated, others breaking down 

 into simpler products." This latter conclusion has been well estab- 

 lished; the others, as stated by Halliburton, require some modification, 

 on the one hand, through the results of later analyses of chromatin, 

 on the other, because of the failure to distinguish between the nucleo- 

 proteids and the nucleo-albumins. First, it has been shown by 

 Miescher ('96), Kossel ('96), and Mathews ('97, 2) that the chromatin 

 of the sperm-nuclei (in fish and sea-urchins) is not pure nucleinic acid, 

 as Altmann conjectured, but a salt of that acid, with histon, protamin, 

 or a related substance. Thus, in the spermatozoa of the salmon, 

 Miescher's analyses give 60.56% of nucleinic acid and 35.56% of 

 protamin (CjgH.28Ng02). In the herring the chromatin is a compound 

 of nucleinic acid (over 63%) and a form of protamin called by Kossel 

 " clupein " (CgQH.-Nj-Og). In the sea-urchin Arbacia Mathews finds 

 the chromatin to be a compound of nucleinic acid and " arbacin," a 

 histon-like body. Kossel finds also that chromatin (nuclein) derived 

 from the thymus gland, and from leucocytes, is largely a histon 

 salt of nucleinic acid, the proportion of the latter being, however, 

 much less than in the sperm-chromatin, while albumin is also present. 

 In these cases, therefore, the greater part of the nucleinic acid is com- 

 bined not with albumin but with a histon or protamin radical. Second, 

 the nucleo-albumins of the cytoplasm are in no sense transitional be- 

 tween the nucleins and the albumins, since they contain no true 

 nucleinic acid, but only pseudo-nucleinic acid.^ The fact nevertheless 

 remains that the nucleins and nucleo-proteids, though confined to the 

 nucleus, form a series descending from such highly phosphorized 

 bodies as the sperm-chromatin toward bodies such as the albumins, 

 which are especially characteristic of the cytoplasm ; and that they 

 vary in composition with varying physiological conditions. The way 

 is thus opened for a more precise investigation of the physiological 

 role of nucleus and cytoplasm in metabolism. 



3. Staining-reaction of the Nuclem Series 



In bringing these facts into relation with the staining-reactions of 

 the cell, it is necessary briefly to consider the nature of staining- 

 reactions in general, and especially to warn the reader that in the 

 whole field of " micro-chemistry " we are still on such uncertain 

 ground that all general conclusions must be taken with reserve. 



First, it is still uncertain how far staining-reactions depend upon 

 chemical reaction and how far upon merely physical properties of 



^'93, P- 574- ^<7^P-33i- 



