January 3, 1902.] 



SCIENCE. 



19 



ousness with which Professor Loeb takes him- 

 self and his work. Every sentence indicates 

 that he realizes the importance of the study 

 of life phenomena, and appreciates the inti- 

 mate relationship of all physiological investi- 

 gation to the practical problems of our work- 

 a-day life. 



The book is itself a collection of experimen- 

 tal! discovered facts of neural physiology so 

 arranged that they inevitably lead the reader 

 to the definite conception of the role of the 

 nervous system held by the author. Note- 

 worthy is the fact that a majority of the ex- 

 perimental studies from which evidence is 

 drawn in support of the views presented have 

 been made by Professor Loeb himself. They 

 form, as thus gathered together, and unified by 

 a single purpose, a splendid monument to the 

 energy, patience and enthusiasm of a physiolo- 

 gist who has well earned the praises of the 

 scientific world. To say of most physiologists 

 'he has based a general discussion of the func- 

 tion of the nervous system solely upon the re- 

 sults of his own researches,' would be equiv- 

 alent to characterizing and condemning the 

 work as narrow and incomplete. But of the 

 work in question this cannot be said, for Pro- 

 fessor Loeb's investigations have covered such 

 a wide range of physiological and psychological 

 phenomena, and his problems have been se- 

 lected with such rare insight into the general 

 implications and relative importance of differ- 

 ent aspects of his chosen work, that they fur- 

 nish an excellent foundation for the theories 

 which he presents. 



The conscious and avowed goal of Professor 

 Loeb's researches is 'the control of life phe- 

 nomena.' His slogan well might be 'more life 

 and fuller that we want.' It is not simply to 

 understand the functions of the organism for 

 the sake or satisfaction of understanding, but 

 that we may be the better able to regulate our 

 lives that we should strive toward the control 

 of vital processes. Toward this goal we are 

 to progress by the use of the methods of phys- 

 ics and chemistry. To quote, "It seems to me 

 that living organisms are machines and that 

 their reactions can only be explained accord- 

 ing to the same principles which are used by 

 the physicist." On the basis of the physical 



and chemical qualities of protoplasm our au- 

 thor proposes to explain all activities. 



'Comparative Physiology of the Brain and 

 Comparative Psychology' may for review be 

 divided into four parts. Of these the first deals 

 with the relation of reflex action to the nerv- 

 ous system. Experimental evidence is pre- 

 sented to prove that such actions are not de- 

 pendent upon any specific character of nerve 

 tissue, but upon the general properties of pro- 

 toplasm. This is followed by a consideration 

 of the morphological and physiological evi- 

 dence bearing upon the 'center theory' and the 

 'segmental theory' of the nervous system, with 

 a defense of the latter. The third main sub- 

 ject is the relation of instinctive action to the 

 role of the nervous system and to reflex action. 

 Experiments are cited to show that the in- 

 stinctive act is really only a chain of reflexes. 

 Finally, in the portion of the book which comes 

 under the title 'comparative psychology,' asso- 

 ciative memory is pointed out as the psychic 

 fact of prime importance. Its connection with 

 brain functioning is discussed, and the possi- 

 bility of analyzing all complex psychic phe- 

 nomena into associative processes maintained. 



It is common to refer all actions to nerve 

 centers. Even the simplest reflex act is thought 

 of by many as dependent upon the functioning 

 of a ganglionic center. Now it is Professor 

 Loeb's conviction that this is an erroneous 

 view; and by an examination of experimental 

 studies of representatives of the Ccelenterata, 

 Echinodermata, Vermes, Arthropoda, Mollusca 

 and Vertebrata he proves that reflexes can be 

 executed in the absence of ganglia. A few of 

 the instances mentioned in the book may be 

 cited. 



Study of the Medus83 has shown that the 

 bell will make normal spontaneous, coordinated 

 movements after the nervous system has been 

 removed. Thus by a very simple experiment, 

 spontaneity, coordination and reflex action are 

 proved to be independent of the central nerv- 

 ous system. 



Among the Ascidians, Ciona intestinalis, 

 whose nervous system consists of a single gan- 

 glion, normally exhibits a peculiarly character- 

 istic reflex in the closing of both the oral and 

 aboral openings, when open, if either is 



