12 ENDOCRINE THERAPEUTICS 



Seeing, then, that we are encompassed about by 

 so great a cloud of enemies, it were surely folly 

 to try to stay them by direct attack only. It 

 must become more or less a trench warfare of 

 defence : our phagocytes and our endocrine 

 glands can in health deal with any ordinary 

 assault ; these are our ^uXa/ee?, our real pro- 

 phylactics. When we realize their importance 

 we grasp the fact that non-immunity is chiefly 

 due to blood and endocrine deficiency, and that 

 here lies our main hope of waging successful war. 

 The production of immunity by vaccines and sera 

 is an established fact and a great ally, but mani- 

 festly too inaccessible for the daily help of the 

 multitude. We must look unceasingly to the 

 garrison and see that its members are in good health 

 and sufficiency. This we can do by curing 

 anaemia, and by finding out if there is any gland 

 in error, an error which is not always obvious, 

 but which soon becomes a most interesting in- 

 vestigation. In substitution treatment by the 

 corresponding animal glands we can generally 

 effect our purpose, and by these means we can 

 also re-educate the defective glands to take up 

 again their proper work. This can readily be 

 done in early and middle life, but in old age the 

 substitution treatment will often have to be 



