732 INTERNAL SECRETIONS AND PRESERVATION OF LIFE. 



trypsin absorbed by the latter. "Just as amceba? digest their 

 prey with the aid of amibodiastase, a soluble ferment belonging 

 to the group of trypsins," writes Metchnikoff, 68 "white corpus- 

 cles submit the foreign bodies they inglobe to the action of 

 cytases. These cytases (the alexins or complements of other 

 authors) are the soluble ferments which also belong to the 

 category of trypsins." It is necessary to bear in mind, how- 

 ever, that, the physiological role of the neutrophile as we have 

 conceived it is foreign to immunity, i.e., to the production of 

 myosinogen and fibrinogen, and that what trypsin penetrates 

 into this cell acts only under normal conditions as a digestant 

 upon the bacilli, and is not, therefore, eliminated as such by 

 the cell. It seems evident, therefore, that Metchnikoff is right 

 when, as stated by Welch, he "strenuously insists . . . that 

 the complement or cytase is within the leucocytes, from which 

 it is not secreted." Still, this does not give us the clue to the 

 manner in which the general blood-stream is supplied with pro- 

 tective toxin-destroying bodies. 



The neutrophiles, which represent three-fourths of all 

 white cells found in the blood, appear as the normal agents for 

 this purpose; but how reconcile the fact emphasized by Metch- 

 nikoff that his trypsin-laden cytase does not leave these cells? 

 This is perhaps explained by another quotation from his text 69 : 

 i.e., "The cytases must be classed among soluble ferments 

 which do not leave the phagocytes while these remain intact. 

 But as soon as these cells are injured they allow a portion of 

 their cytases to escape from their contents." If this is the only 

 process through which the blood is supplied with its trypsin, we 

 are led to the deduction that in all intoxications due to albumi- 

 noid bodies injury to neutrophiles is necessary: an inapplicable 

 mechanism in the general blood-stream when general infections 

 are present. Indeed, we have not been able to find in this 

 distinguished zoologist's work evidence that the phagocytes 

 at any time part with their cytase for the purpose of distribut- 

 ing it throughout the organism. He only refers to the elimina- 

 tion of the trypsin-containing substance as passing out of the 

 cells after these have been taken from the organism: i.e., extra 



68 Metchnikoff: Loc. cit., p. 573. 

 Ibid. 



