246 MEDICINE 



into the blood a substance which has been called 

 'secretin.' A supply of this substance in the 

 blood is immediately secured therefore when the 

 acid contents of the stomach enter the intestine. 

 But by secretin the pancreas is affected as by no 

 other substance, and when the blood which leaves 

 the intestinal wall charged with secretin passes 

 through the pancreas the gland is immediately 

 stimulated to pour, by way of its duct, its special 

 digestive fluid into the cavity of the intestine, 

 where the partially digested food from the stomach 

 awaits its action. Thus, automatically, are the 

 physiological events adjusted in due sequence. 



Turning now to the internal secretion of the 

 pancreas, a product of quite another character, 

 we have learnt from abundant experiments that 

 its presence is absolutely necessary to all the 

 living tissues of the body. In its absence the 

 sugar which normally provides energy for their 

 activities escapes utilisation, and the whole animal 

 becomes diabetic. One organ caters for the needs 

 of every other organ in the body. 



Who, having visited the valleys of the Alps, 

 is unfamiliar with the painful aspect of the cretin ? 

 The cretin's condition is due to failure in infancy 

 of the internal secretion of the thyroid gland. 

 Without a proper supply of this, the young body 

 fails to grow into the normal semblance of mankind. 

 If the same gland first loses its activity in later 

 life the condition of Myxoedema results. The 



