202 Literary Notices. 



logical literature. It is reasonably self-explanatory, simple and direct and as 

 employed by the author it serves the excellent end of enabling him to speak of 

 objective and subjective facts without confusion. 



Lectures I, II and III, coordination in the simple reflex, discuss the nature of 

 the structural and the functional units of the nervous system (the neurone and the 

 nerve-arc) and of the interconnection of the various parts of the body through the 

 integrative action of the nervous system. The phenomena of refractory phase and 

 inhibition are dealt with at length and in a most illuminative manner. Lecture IV, 

 interaction between reflexes, points out the artificiality of the conception of the 

 simple reflex, the features of reflex-arc functions which result in the harmonious 

 compounding of reflexes and the existence of two important classes of reflexes, the 

 allied and the antagonistic, the mutual relations of which provide us with the mani- 

 fold phenomena of facilitation and inhibition. 



Lectures V and VI, compound reflexes, are devoted, the first to simultaneous 

 combination of reflexes, the second to successive combination. In connection with 

 simultaneous combination it is made clear that Pfluger's laws of spinal irradiation 

 are contradicted by many of the facts of the author's investigations. Under the 

 subjects, irradiation and "reflex pattern" the main features of the simultaneous 

 compound reflex are thoroughly discussed. In the lecture on successive combina- 

 tion chain-reflexes receive attention. The current theories of inhibition are 

 examined. Noci-ceptive (pain) nerves are shown to bring about reflexes which 

 are prepotent. Lecture VII, reflexes as adapted reactions, is an excellent discus- 

 sion of the purposes of reflexes and of the conditions which reveal and conceal the 

 same. Lecture VIII, some aspects of the reactions of the motor cortex, in addi- 

 tion to giving with delightful clearness the topography of the motor cortex of the 

 chimpanzee, the orang-outang and the gorilla, suggests the relation of the motor 

 cortex to receptors (sense .' organs), more especially to distance receptors. Lecture 

 IX, the physiological position and dominance of the brain, adds to a splendid 

 resume of the results discussed in the previous lectures, a convincing array of facts 

 in support of the contention that the cerebrum is preeminently the ganglion of the 

 distance-receptors, the cerebellu-m the ganglion of the proprio-ceptive (that is, the 

 internal as contrasted with the surface-receptor) system. Lecture X, sensual fusion, 

 consists of a comparison of the nervous integration of movement and of sensation 

 by reference to results of the study of certain visual phenomena. 



Of the three prominent points of interest from which the functions of the ner- 

 vous system may be studied, metabolism, conduction and integrative action, this 

 series of lectures deals almost exclusively with the last. This integrative or inter- 

 connecting activity of the nervous system which serves to make of the complex 

 multicellular organism a functional unit of a high degree of efficiency is in large 

 part the coordination of parts of the body by reflex action. Structurally the unit 

 of the nervous system is the neurone, functionally it is the nerve-arc, which consists 

 in its simplest form of a receptor and an effector which are linked by a conductor. 

 The series of functional stages in the action of the nerve-arc may be termed initiation, 

 conduction and end-effect. So far as integrating activity is concerned the reflex- 

 arc is the unit of mechanism, the reflex-act the unit of reaction. And a reflex-act, 

 according to the author, is a reaction "in which there follows on an initiating reac- 

 tion an end-effect through the mediation of a conductor, itself incapable either of 

 the end-effect or, under natural conditions, of the inception of the reaction" (p. 6). 



