November 12, 1915] 



SCIENCE 



697 



■when needed. This is illustrated by the violent 

 beating of the heart in anger, and by other 

 activities of the organism discussed more fully 

 below. The third has mainly to do vfith the 

 preservation of the species, and involves the 

 action of the sexual organs. ■■■ 



Dr. Cannon points out that the sympathetic 

 division operates antagonistically and inhibi- 

 tively in its relation to the other two divisions, 

 stimulating organs which they depress, or 

 vice versa. Broadly speaking, it is the more 

 imperious in its demands, and is likely, when 

 in action, to dominate the others. 



In connection with the operation of the 

 sympathetic under the influence of pain or 

 great emotional excitement, certain highly 

 interesting glandular effects are observed. 

 Adrenin is secreted and thrown into the cir- 

 culation by the adrenal glands; additional 

 sugar is also found in the blood. Experiments 

 show that the adrenin is a powerful antidote to 

 fatigue phenomena, and that it tends to drive 

 the blood away from the abdominal organs into 

 the lungs, heart and skeletal muscles, and that 

 under its influence breathing is made deeper. 

 It may be added that with these general con- 

 ditions blood is found to clot more rapidly than 

 under normal circumstances. 



It has of course been a matter of general 

 knowledge for generations that emotional 

 excitement releases resources of muscular 

 energy much in excess of those ordinarily at 

 disposal. Human achievement in battle, in 

 exciting sports, in terror and rage are all in- 

 stances of this. These researches and others 

 cited in support of the conclusions reached 

 indicate more exactly the mechanisms by 

 ■which the commonly observed results are actu- 

 ally brought about. Especially do they tend 

 to magnify the of£ce of the adrenal glands, 

 organs whose functions have until recently been 

 shrouded in mystery. 



In common with other leading physiologists 

 Dr. Cannon regards the sensation of hunger 

 as due to contractions of the stomach wall in 



1 One may suppose that Dr. Canon does not re- 

 gard as important the suggestions of certain scien- 

 tists that these organs are in fact largely controlled 

 by plexuses derived from the sympathetic. 



contra-distinction to the other hypotheses in 

 the field ; e. g., the theory that hunger is a gen- 

 eral bodily sensation, that it is due merely to 

 emptiness of the stomach, that it arises from 

 hydrochloric acid in the empty stomach, etc. 

 The chapter dealing with this topic, while 

 intrinsically interesting, at first sight articu- 

 lates with the rest of the volume somewhat 

 indirectly. But when the distinction between 

 appetite and hunger is remarked the relevancy 

 of the material to the general theses of the 

 book becomes apparent. Appetite has to do 

 with suggestions of the agreeableness of food, 

 in which sight, taste, smell and the activity of 

 memory are definitely implicated. Hunger is 

 a painful process which often, indeed generally, 

 coincides with appetite, but it may exist with- 

 out it, or may be wanting when appetite is 

 present. Hunger springs from a definite local 

 source, and involves vigorous action of the 

 sympathetic. Appetite is more definitely 

 psychical, and involves the cranial autonomic 

 rather than the sympathetic. This distinction 

 in the case of hunger and appetite afl^ords a 

 moderate instance of the antagonistic emotional 

 interrelations which are often much more ex- 

 treme and intense. Dr. Cannon elaborates 

 these antagonisms by exhibiting various emo- 

 tional expressions in which the sympathetic 

 system is shovm acting in vigorous opposition 

 to the cranial and sacral. Perhaps the most 

 striking instance is that of sexual emotion 

 which despite its overwhelming power when 

 once aroused can be inhibited absolutely by 

 such activities of the sympathetic as are repre- 

 sented in fear and anger. 



The author annexes as a final chapter to the 

 book a discussion of alternative satisfactions 

 for the fighting instincts and emotions. One 

 is reminded of William James's brilliant paper 

 on the moral equivalents for war. Like James 

 Dr. Cannon concludes that the fighting in- 

 stincts are too deeply inbred to be speedily 

 exterminated, even if such extermination were 

 thought wise. In order that they may not be 

 perverted nor yet allowed to occasion unlimited 

 human misery, by their normal expression, he 

 advocates athletic competition of all kinds, and 

 especially international games. The issue here 



