No. I.] BLOOD CORPUSCLES. HI 



they stain alike, except that the blood plates take the stain 

 more feebly. In the case already mentioned, in which the 

 preserved blood was treated with a differential stain, successive 

 staining in hasmatoxylin, eosin, and saffranin, the blood plates, 

 like the nuclei of the leucocytes, took the hcematoxylin. The 

 same is true of methyl violet (Gibson) and methyl green. If 

 this view of the life-history of the leucocytes of the blood is 

 correct, it seems probable that they play an important part 

 in the formation of the blood proteids. The young lympho- 

 cytes increase in size by the formation of new protoplasm ; 

 and in the end this again passes into solution in the plasma. 

 Schmidt long ago stated that the paraglobulin of the blood is 

 derived from disintegrated leucocytes. In fact, if I under- 

 stand him correctly, he believes that the paraglobulin is all 

 formed in this way after the blood is shed. Later investiga- 

 tions of the serum and plasma have shown that this latter 

 statement is not correct, though there is apparently an increase 

 in the amount of paraglobulin in the serum over that in the 

 plasma. Still, it may be considered probable that the para- 

 globulin of the blood is derived wholly from the breaking down 

 of the leucocytes, and that the constant supply of paraglobulin 

 in the blood is derived from the continual disintegration of the 

 multinucleated leucocytes. The fibrinogen, on the other hand, 

 is possibly derived from the liberated and dissolved nuclei of 

 the mature nucleated red corpuscles, and perhaps of the blood 

 plates also, if they, too, represent nuclear material. We 

 know little or nothing at present of the genesis and relation- 

 ship of the blood proteids or of the nutritive value and signifi- 

 cance of each. The fact that their percentage amounts in the 

 plasma remain practically constant under many different con- 

 ditions of nutrition indicates that they are regenerated contin- 

 ually in proportion as they are used up ; but how this happens 

 is one of the darkest as well as one of the most interesting 

 points in the physiology of the blood. It seems to me that 

 the question must be studied, in part at least, upon the hy- 

 pothesis of their derivation from the formed elements of the 

 blood in the manner here suggested, somewhat as we look 

 upon the ground substance, or matrix, of the connective tissues 

 as having its origin from the cellular elements. 



