METABOLISM, NUTRITION AND DIETETICS 571 



known as ^-hydroxyphenylethylamine, formed from tyrosin (Barger 

 and Walpole). 



The spleen does not produce an internal secretion necessary to 

 life, for it can be removed both in animals and in man, not only 

 without causing death, but often without the development of any 

 serious symptoms. Its blood - forming and blood - destroying 

 functions (p. 21) are taken on by other structures (particularly the 

 red bone-marrow), but the formation of the bile-pigment is inter- 

 fered with, and its amount reduced by more than 50 per cent. 

 (Pugliese). The production of trypsinogen by the pancreas is also 

 said to be diminished, whereas if an extract of spleen be injected 

 into the circulation of an animal deprived of its spleen, the amount of 

 trypsinogen is increased. It has, therefore, been supposed that the 

 spleen forms a substance (protrypsinogen) which, passing into the 

 blood, is taken up by the pancreas and elaborated into trypsinogen 

 (P- 382). 



The salivary glands may be extirpated without any sensible 

 change being produced in the normal metabolism. There is evidence, 

 however, that the secretion cf the gastric juice is diminished. It 

 has been supposed that this may be due to the absence of a hormone 

 (P- 375) normally produced in the salivary glands. A temporary 

 increase in the gastric secretion is caused when extracts of the 

 glands cf normal dogs are injected into the veins or into the 

 peritoneal cavity of dogs deprived of their salivary glands 

 (Hemmeter). 



Extracts of the pineal gland injected into the circulation have 

 no effect other than that due to the inorganic constituents of the 

 ' brain sand/ 



