684 INTERNAL SECRETIONS AND PRESERVATION OF LIFE. 



the corpuscle is merely an example of what seems to be a general 

 rule (to which, however, there may be exceptions) that, while 

 the elements of the tissues themselves are rich in potassium 

 and phosphates, th'e blood-plasma on which they live abounds 

 in chlorides and -sodium salts." 



The chemical process involved may easily be traced with 

 the foregoing factors as main elements: The blood-plasma (if 

 the views already submitted are sound) evidently reaches the 

 nucleus through the intracanalicular substance of the cell-body; 

 this is shown by the fact that this substance likewise though 

 to a less-marked degree stains with methylene-blue. Under 

 ordinary circumstances, according to microscopical evidence, 

 the perinuclear vacuole is practically collapsed: i.e., its nuclear 

 wall is more or less close to that of the cell-body. This is well 

 shown in Gulland's plate, by Figs. 10 and 12. The nucleus 

 thus bathes in blood-plasma, and its canaliculi become filled 

 with the latter along with the vacuole. The nuclein of the 

 nucleus under these circumstances itself bathes in the plasma, 

 being thus exposed to the action of the latter's oxidizing sub- 

 stance. 



Still, this suggests the presence of a stream of plasma 

 flowing through the nucleus itself, with the canaliculi as emunc- 

 tories. The contraction and retraction of the canaliculi or 

 reticulum to which Gulland and others refer represent the 

 only mechanical device in the cell by means of which the 

 vacuole can be drained. 



These minute vessels probably serve as continuous chan- 

 nels for the stream of plasma, which contains, besides the 

 oxidizing substance, the alkaline salts necessary to the intra- 

 cellular processes. The plasma's oxidizing substance and the 

 nuclein's phosphorus, thus brought into contact, liberate con- 

 siderable heat, and the alkaline salts in the plasma then take 

 part in the reaction to which Williams refers, and which in- 

 volves, we have seen, the formation of phosphoric acid and 

 other agencies to which we will presently allude. 



We must not lose sight of the fact, however, that nuclein 

 is derived from nucleo-proteids, and that during the oxidation 

 process waste-products are formed: we have in the "adenin, 

 sarcin, xanthin, spermin, etc.," to which Williams refers, a 



