xvi Journal of Comparative Neurology. 



time is not yet ripe for it, as our fund of knowledge is still far too 

 meager. But this work does give a very faithful picture of the status 

 at the present moment; and it is much more than this, for Dr. Barker 

 has done what some of our pioneers in the newer fields have signally 

 failed to do — he has corrolated these newer findings with the classical 

 works by the older methods. Herein perhaps lies the chief value of 

 the work, for the bibliographic labor expended has been enormous and 

 the facts are presented in such a way as to be really accessible to the 

 reader so far as they go without consulting the original papers. This 

 is largely due to the surpassing richness and excellence of the illus- 

 trations. 



As a work of reference, therefore, it is invaluable, since it gives 

 quite complete pictures of the whole of our knowledge regarding every 

 detail of the structure touched upon. The book falls into six sections, 

 as follows: (i) The History of the Development of the Neurone Con- 

 cept, (2) The External Morphology of Neurones, (3) The Internal 

 Morphology of Neurones, (4) The Histogenetic Relations of the Neu- 

 rones, (5) The Neurone as the Unit in Physiological and Pathological 

 Processes, (6) On the Grouping and Chaining together of Neurones in 

 a Complex Nervous System like that of Man and Higher Animals. 

 The last section includes more than two thirds of the entire work. The 

 fourth section is undoubtedly the weakest, the materials not being 

 chosen from as wide a field as might be desired, nor are those selected 

 very well organized. As illustrating the difficulties in the classification 

 of the matter, one notices that, though a chapter in Section 4 is de- 

 voted to the segmentation of the body, yet the most important data on 

 this subject are to be found in two other places, in connection with the 

 sensory and motor nerves in Section 6. It would seem better to have 

 brought these together, even at the expense of logical analysis. 



The work is not well adapted for an elementary text-book, the ma- 

 terial presented being too voluminous and much of it too technical; it was 

 doubtless not so intended, as evidenced by the absence of any syste- 

 matic presentation of the general gross topography. As a reference 

 book there are a few points in which improvements might be suggested. 

 For example, the bibliographical citations would be of much more 

 value for easy consultation if they were gathered together at the 

 close of the work instead of scattered in foot notes. This too would 

 have saved some repetition — an important item in a book as large as 

 this. The latter point applies also to the figures, some of which are 

 repeated many times, when a simple cross reference would have an- 

 swered as well and materially decreased the number of pages. The 



