702 INTERNAL SECRETIONS AND PRESERVATION OF LIFE. 



the latter, but also that fibrinogen subserves the same purpose in 

 the blood that myosinogen does in muscle: i.e., it supplies it with 

 its primary source of functional energy. 



True, the solubility of fibrin differs somewhat from that 

 of myosin, but 'this is probably due not to a difference in the 

 molecular structure of fibrinogen as against that of myosinogen, 

 but to the influence of the medium in which the granules are 

 dropped by the leucocyte. Indeed, the ashes of fibrin contain 

 a larger proportion of calcium and magnesium phosphate than 

 does myosinogen. 



Another conclusion which now seems to us warranted is that 

 the neutrophile leucocytes are the agencies which take up proteids 

 in the intestinal canal, and, after submitting them to a process in 

 which various physio-chemical bodies taken up by them in the portal 

 and hepatic systems take part, distribute the products to every part 

 of the organism^ including the blood itself. 



Such being the case, the proteids, inclosed in their diminu- 

 tive carriers, should not be found in the blood of the portal 

 system. Professor Foster writes, in this connection, after re- 

 ferring to the difficulties attending the experimental determina- 

 tion of the path taken by proteids: "Bearing this in mind, we 

 may state that all observers are agreed that peptone is absent 

 from chyle, or at least that its presence cannot be satisfactorily 

 proved. On the other hand, while some observers have suc- 

 ceeded in finding peptone in the portal blood after food, but 

 not 'during fasting, many have failed to demonstrate the pres- 

 ence of peptone in the blood either of the portal vein or of the 

 vessels at large, even after a meal containing large quantities of 

 proteids." Again: "If an artificial circulation of blood be kept 

 up in the mesenteric arteries supplying a loop of intestine 

 removed from the body, the loop may be kept alive for some 

 considerable time. During this survival a considerable quan- 

 tity of peptone placed in the cavity of the loop will disappear: 

 i.e., will be absorbed, but cannot be recovered from the blood 

 which is being used for the artificial circulation, and which 

 escapes from the veins after traversing the intestinal capil- 

 laries. The disappearance is not due to any action of the blood 

 itself , for peptone introduced into the blood before it is driven 

 through the mesenteric arteries in the experiment may be re- 



