132 The Unity of the Organism 



(2) That emotional excitement (as the fright of a cat by 

 a dog) similarly increases the flow of adrenin. 



(3) That this increase of adrenin in the blood may in- 

 crease the liberation of sugar from the liver into the blood 

 to such an extent as to make sugar appear in the urine, thus 

 demonstrating a true "emotional glycosuria." 



(4) That the increased adrenin of the blood thus pro- 

 duced is probably advantageous to the organism in that it 

 enhances its ability to meet special stresses that naturally 

 accompany special excitement, as of fear, anger, or pain, 

 this advantage consisting partly in augmentation of the 

 working energy of the muscles, probably through the sugar 

 delivered to them, and in increasing the coagulability of the 

 blood, thereby reducing the danger from bleeding wounds. 



Summing up his conclusions as to utility, Cannon writes : 

 "These changes in the body are, each one of them, directly 

 serviceable in making the organism more efficient in the 

 struggle which fear or rage or pain may involve; for fear 

 and rage are organic preparations for action, and pain is 

 the most powerful known stimulus to supreme exertion. The 

 organism which with the aid of increased adrenal secretion 

 can best muster its energies, can best call forth sugar to 

 supply the laboring muscles, can best lessen fatigue, and can 

 best send blood to the parts essential in the run or the fight 

 for life, is most likely to survive." 24 



But fear and rage are, one hardly need be reminded, in 

 part psychic phenomena, and hence inseparably connected 

 with the higher centers of the cerebrospinal nervous system. 

 Though in the main reflex and automatic, they are neverthe- 

 less to some extent subject in man to intelligent control. 

 Thus the way is open for a measure of rational understand- 

 ing of the structural-functional means by which human be- 

 ings "tap," as William James would say, and bring under 

 direction those remarkable "reservoirs" of ordinarily unused 

 energy about which everybody knows something from his 



