Literary Notices. 207 



to a disorder of coordination which, though not necessarily of itself accompanied 

 by physical pain, inflicts on the mind, which still remains clear, a disability in- 

 expressibly distressing. Each attempt to execute certain muscular acts of vital 

 importance, such as the taking of food, is defeated because from the attempt results 

 an act exactly the opposite to that intended. The endeavor to open the jaw to 

 take food or drink induces closure of the jaw, because the normal inhibition of 

 the stronger set of muscles — the closing muscles — is by the agent converted into 

 excitation of them" (p. 298). 



Sherrington's work has discovered the existence of two systems of innervation 

 controlling two sets of musculature. These systems are named by him the phasic 

 and the tonic reflex systems. "The phasic system exhibits those transient phases 

 of heightened reaction which constitute reflex movements; the tonic system main- 

 tains that steady tonic response which supplies the muscular tension necessary to 

 attitude" (p. 302). 



If receptors be classified as those which receive impressions which are referred 

 beyond the organism (Sherrington's distance-receptors) and those whose im- 

 pressions are referred to the organism (proprio-receptors), it is to be noted that the 

 cerebellum is the main ganglion of the proprio-ceptive system, while the cerebrum 

 stands in a like relation to the distance-receptors. "It is the long serial reactions 

 of the "distance-receptors" that allow most scope for the selection of those brute 

 organisms that are fittest for survival in respect to elements of mind. The "dis- 

 tance-receptors" hence contribute most to the uprearing of the cerebrum. One 

 of the most important of the groups of proprio-ceptive organs is that of the laby- 

 rinth, and these together with those other receptors whose chief function is the con- 

 trol of attitude have as their center of reference the cerebellum. The distance- 

 receptors, and therefore the cerebrum, are the chief inaugurators of reaction; the 

 proprio-ceptors, and therefore the cerebellum, control the habitual taxis of the 

 skeletal musculature. 



In the lecture on sensual fusion it is shown that the fusion of sensation does not 

 follow the rules which have been established for the fusion of reflexes. "The 

 cerebral seats of right-eye and left-eye visual images are thus shown to be separate 

 (referring to an experiment previously described.) Conductive paths no doubt 

 interconnect them, but are shown to be unnecessary for visual unification o( the 

 two images. The unification of a sensation of composite source is evidently asso- 

 ciated with a neurone arrangement different from that which obtains in the synthesis 

 of a reflex movement by the convergence of the reflexes of allied arcs upon its final 

 common path" (p. 383). 



Finally, it should be mentioned that Sherrington firmly believes in the right 

 of psychology to existence and in the mutual helpfulness of physiology and psy- 

 chology. Their workers should, in his opinion, give close attention to one another's 

 results. Of comparative psychology he says: "Despite a protest ably voiced by 

 v. Uexkull, comparative psychology seems not only a possible experimental 

 science but an existent one" (p. 307). 



A few months ago in reviewing Jennings' "Behavior of the Lower Organisms"' 

 I saw good reason to characterize it as the most important book on animal behavior 

 that had ever been written. To that statement of my opinion I may now add that 



' Jour, of Phil., Psy. and Scientific Methods. Vol. 3, p. 658. 1906. 



