Literary Notices. cxcv 



sciousness, but only their coordination, so there must be some place in 

 the body in which the mechanism for this coordination may be ef- 

 fected. True self-consciousness arises only upon the occasion of a 

 state of tension, or distinction of equilibrium among the various feel- 

 ings. The concentration of feelings into self-consciousness has arisen 

 under the influence of impediments to the free play of reflex 

 movements. 



Chapter X, on The Seat of Consciousness has been re-written. 

 Dr. Carus' article in the September number of this Journal presents 

 the substance of this chapter and the reader is referred to it for the 

 detailed exposition. 



C. J. H. 



Invertebrate Morphology. 1 



This new text-book is adapted to the needs of students of some 

 maturity, rather than to young beginners. The matter is arranged 

 in a strict taxonomic order, so that the book may be used as a general 

 text-book of invertebrate Zoology and as such it will doubtless find a 

 wide usefulness in our colleges and other schools of higher learning. 

 The attempt has been made to bind the facts of comparative anatomy 

 together by such morphological bonds as will not only show the true 

 relationships of the organisms, but also something of the rationale of 

 the process by which the differentation has been effected. The book 

 contains more of description than of explanation, as must necessarily 

 be, in the present unsettled state of our knowledge. All of the the- 

 oretical questions centering about phylogenesis are today so hotly de- 

 bated that a disappointing meagerness of positive morphological con- 

 clusions can be readily condoned if those which are chosen are care- 

 fully considered and based on sound principles. Professor McMur- 

 rich has succeeded in producing a book which, while taking cogni- 

 zance of all that is best in current theory, yet maintains a conserva- 

 tive attitude and presents conclusions which may almost always be re- 

 lied upon. 



The new departures which probably first catch the eye of the 

 reader are in the classification adopted. The invertebrates are divided 

 into no less than twelve primary types. We find as distinct types the 

 Prosophygia (Molluscoidea), Platyhelminthes, Nemathelminthes, An- 

 nelida, Crustacea, Arachnida, Tracheata, Protochordata. The latter 



'McMurrich, J. Playfair. A Text-book of Invertebrate Morphology. 

 New York. Henry Holtb* Co., 1894, pp. 661. 



