94 THE PROTEOMORPHIC THEORY AND THE NEW MEDICINE 



But where is the census-taker of blood corpuscles who has sig- 

 naled to them that these exceptional recruits are needed? 



The more one considers that problem the more puzzling it 

 seems ; particularly in view of the fact that the bone marrow is 

 but doubtfully connected with the nervous mechanism. There 

 are sympathetic nerves in connection with the blood-vessels, to 

 be sure, and these might serve to modify the blood supply; but 

 we can scarcely suppose that this by itself can control the activ- 

 ities of the cytogenic cells, particularly if we recall that the blood- 

 pressure may be increased indefinitely without necessarily caus- 

 ing leucocytosis ; whereas, on the other hand, active generation 

 of leucocytes may occur after a hemorrhage that has reduced 

 blood-pressure to the minimum. 



It does not necessarily follow from this that the sympathetic 

 nervous system may not have a share in determining the activ- 

 ities of the cytogenic cells. The nervous mechanism may well 

 be supposed to take part in the co-ordinating of the activities 

 of the various mother cells, located in bone marrow and spleen 

 and widely scattered lymph nodes. But there is another and 

 quite different stimulating and co-ordinating mechanism which 

 recent studies have brought into the foreground, namely the 

 endocrinous system, with its various internal secretions and 

 hormones. 



The messengers of this system travel in the blood stream itself, 

 as also doubtless in the lymph stream, and there is a good deal 

 of evidence pointing to these agents as the stimulators and reg- 

 ulators of cytogenic activity. 



I have had verbal report from a colleague of cases of dia- 

 betes and Graves' disease, in which the therapeutic exhibition 

 of the duodenal hormone, secretin, is reported to have led to a 

 rapid and extraordinary rise in the blood count, including both 

 leucocytes and erythrocytes. It is interesting to note, as strongly 

 supporting the Proteomorphic theory, that this corpuscular in- 

 crease is said to have coincided with very marked amelioration 

 or total disappearance of the symptoms of protein poisoning 

 that characterize the disease. But at the moment our attention 

 is directed to the probably direct connection between the exhi- 

 bition of secretin and the increased activities of the cytogenic 

 cells. 



It has been clearly demonstrated that secretin, as produced in 

 the duodenum, enters the blood, and being carried to the pan- 

 creas, stimulates that organ to the production of its charac- 

 teristic tryptic enzymes. What more natural than that the same 

 hormone should carry similar messages to the bone marrow to 

 stimulate the production of the leucocytes that are known to 

 secrete an enzyme closely allied to trypsin, and to subserve, 



