248 MEDICINE 



secretion, and the effect of this upon the body as 

 a whole is to make it better prepared to meet the 

 emergency, For fight or for flight ; for any sort of 

 strenuous action, the body needs those immediate 

 adjustments which are produced by an increased 

 flow from the suprarenal glands. This flow is 

 brought about by the nervous disturbances which 

 follow upon a realisation of emergency. Our 

 knowledge of the remarkable relations of these 

 glands has been gradually built up, mainly from 

 the brilliant experimental researches of Schaefer, 

 Langley, and Elliott, as well as others in this 

 country, and from those of Cannon in America. 

 It is one of the triumphs of the chemical side of 

 physiology that the actual chemical substance 

 present in the secretion and responsible for its 

 remarkable effects has been isolated from the 

 glands. Its constitution has been fully determined, 

 and its artificial manufacture accomplished. It is 

 known as Adrenalin. We could now stop any 

 metaphysical discussion concerning the ' cause' of 

 certain at least of the physiological events which 

 accompany emotions by writing the chemical 

 formula of adrenalin upon the blackboard and 

 saying with Pasteur "Tenez, void sa figure!" 

 Facts no less interesting are associated with the 

 internal secretion of the reproductive glands. 

 These, in addition to executing their more ob- 

 vious functions, pour into the blood substances 

 of the profoundest importance to the normal 



