736 FEED C. KOCH 



the donor presumably contains a higher concentration of the active sub- 

 stance in its blood than the recipient, and then detecting this by a char- 

 acteristic physiological response in the recipient. We shall learn that in 

 neither case does the experimental evidence conclusively prove that any 

 of the organs of the digestive tract act truly specifically as endocrine tissues. 

 Nevertheless, it is conceivable that they may act thus, and even if they 

 do not do so, such extracts, if properly prepared, purified and standardized, 

 may be of considerable value clinically. It is, however, not likely that the 

 clinical application will be along the lines of true organotherapy, that is, a 

 substitution as in the case of the thyroid. 



Endocrine Considerations of Various Digestive Organs 



The Salivary Glands. The first observations along these lines were 

 made by J. C. Hemmeter (a) (&) in 1907-8. He concluded that in gastric 

 fistula dogs, extirpation of all of the salivary glands causes a diminished 

 gastric secretion and that this is equally true when the vagi are cut. In 

 such animals he found a decrease in the rate of secretion, as well as in the 

 activity of the gastric juice, but that this could be restored to the normal 

 values by the intravenous injection of extracts prepared from dog's 

 salivary glands, providing these glands were removed when it was known 

 that they were functionally active. He could not bring about this stimula- 

 tion by feeding food, previously chewed and mixed with saliva by other 

 dogs, nor by feeding the salivary glands. He found lymph gland extracts 

 inactive and the spleen slightly active. A. S. Loevenhardt and D. R. 

 Hooker could not confirm the stimulating action of salivary gland extract 

 on normal dogs. In reply to these findings, Hemmeter claims that one can 

 hardly expect to be able to increase a normal secretion. Keeton and 

 Koch (1915) also were not able to stimulate a resting stomach to secretory 

 activity by submaxillary gland extracts, thus confirming the findings of 

 Loevenhardt and Hooker. Swanson (1917), in studies on two dogs, before 

 and after complete removal of the salivary glands, did not observe a de- 

 crease in the rate of secretion or of activity of the gastric juice, as 

 measured by the Pawlow pouch. In fact, after the removal of the 

 salivary glands a more strongly acid juice was obtained; this was 

 very striking in one of the dogs, Hemmeter stands alone in both 

 of his claims; that is, neither the lowered rate of secretion of a weaker 

 juice as the result of removal of the glands, nor the stimulating effect of 

 the salivary glands extract has been confirmed by others. The subject 

 requires further investigation and at present the results do not indicate 

 an endocrine function in the salivary glands. The only other suggestion 

 of a salivary internal secretion is the work of Bruno Farroni, who 1 reports 

 that extracts of salivary glands have a marked glycolytic action on 



