THE PROTEOLYTIC MECHANISM IN OPERATION 95 



within the vascular mechanism, a function of proteid digestion 

 comparable in a small way to that of the pancreas itself? 



In the activities of the hormone secretin, then, if these infer- 

 ences are justified we find a solution of one aspect of the prob- 

 lem of maintenance of the corpuscular balance. This duodenal 

 hormone being available as a messenger, the fact that the tissues 

 of the bone marrow take on fresh activities in response to the 

 taking of food into the stomach seems no longer mysterious, 

 or at least no more mysterious than, for example, the increase 

 in the activities of the pancreas brought about through the same 

 agency. 



There are other conditions, however, in which there is increase 

 in the blood count, where the agents through which the cytogenic 

 mechanisms are stimulated may not be so readily traced. How, 

 for example, shall we explain the leucocytosis that takes place 

 in the course of violent muscular exercise? 



Here the explanation offered must be regarded as altogether 

 theoretical and provisional, although assuredly not lacking in 

 plausibility. The suggestion I would make is that the increase 

 of leucocytes here is due, in part at least, to the increased flow 

 of lymph resulting from muscular contraction. It is known that 

 lymph scarcely flows at all in the lymphatics of the limbs during 

 quiescence, but is stimulated by active or even by passive move- 

 ment. It is known also that lymph flowing through a lymphatic 

 gland is observed to emerge with an increased increment of 

 leucocytes, and the inference seems unavoidable that the leuco- 

 cytes in question were developed in the lymph node. It is a fair 

 inference that their rate of development depends on the rate 

 of flow of the lymph which must bring the food albumen to 

 their mother cells, and if this be admitted the increase in such 

 of the leucocytes as are developed in the lymphatic system as 

 a result of muscular exercise is accounted for. 



The function of the lymphocytes thus brought forth would be, 

 perhaps, to assist in the catabolism of products of protein de- 

 compounding associated with muscular activities (e.g., creati- 

 nine) or of materials (proteins or fats) for supplying foods 

 or fuels to these cells. In the original presentation of the Pro- 

 teomorphic theory it was suggested that this lymphocyte assists 

 in the decompounding of the normal serum proteins. I am now 

 disposed to question the validity of this assumption, but there 

 were certain collateral suggestions that perhaps warrant repro- 

 duction of the paragraphs in question here : 



"A word should be said about the precise service which the 

 lymphocytes thus called forth in response to muscular action 

 render to the muscles that have indirectly engendered them. This 

 lymphocyte is not a phagocyte, but it may have to do with the 



