LITERARY NOTICES. 



7°9 



usual term of segmentation of the ovum, 

 even though he has the precedence afforded 

 by Prof. Huxley's employment of a term that 

 should have been left to its original scientific 

 use in geology and mineralogy. 



The methods of development of the two 

 primary and of the two middle germ layers — 

 the so-called gastraea theory and ccelom 

 theory — are presented in separate chapters. 

 The author maintains that at the close of 

 segmentation there is only one germ layer 

 present — the epithelium of the blastula. 

 From it the remaining germ layers arise by 

 the processes of invagination and evagina- 

 tion — the inner germ layer being formed 

 by means of gastrulation, the two middle 

 germ layers being formed by the formation 

 of the body cavities, in that two body sacs 

 are evaginated from the coelenteron and 

 grow out between and separate the two pri- 

 mary germ layers. After their origin the 

 middle germ layers are differentiated into 

 several fundaments (rudiments) by processes 

 of folding and constricting off. 



The development of the connective sub- 

 stance and blood is explained by means of 

 the mesenchyme germs. This is followed by 

 chapters on the establishment of the external 

 form of the body and on the foetal membranes 

 of reptiles, birds, mammals, and man. 



The consideration of the science of the 

 embryology of organs is divided into four 

 sections, comprising the morphological prod- 

 ucts of the inner, of the middle, of the 

 outer, and of the intermediate germ layers. 

 This is, of course, an arbitrary division, for 

 the teeth arise from the intermediate and the 

 outer germ layers, while the alimentary canal 

 and its glands contain elements from the 

 inner, middle, and intermediate layers. 



Space forbids any extended consideration 

 of the features pertaining to these latter top- 

 ics. The work is certainly a comprehensive 

 presentation of the eubject, and the transla- 

 tor has performed his arduous task in a 

 satisfactory manner. 



Commercial Organic Analysis. By Alfred 

 H. Allen. Volume III, Part II. Phila- 

 delphia : P. Blakiston, Son & Co. Pp. 

 584. Price, $5. 



Each successive portion of this valuable 

 work testifies to the masterly ability with 

 which its author has handled a large and dif- 



ficult undertaking. The present part deals 

 with Amines and Ammonium Bases, Hydra- 

 zines, Bases from Tar, and Vegetable Alka- 

 loids. The substances of chief commercial 

 importance that are treated are, therefore, 

 drugs, such as aconitine, atropine, cocaine, 

 morphine, quinine, and their allies ; the al- 

 kaloids of coffee, tea, and cocoa, and the ani- 

 line colors. Substances of special interest at 

 the present time which fall within the scope 

 of this part are antipyrine and certain other 

 antipyretics. A third part of Volume III is 

 to be issued to complete the treatise, and it 

 is gratifying to note that the success of the 

 work in its enlarged form warrants the author 

 in announcing a new edition of the earlier 

 volumes. 



Railway Injuries, with Special Reference 

 to those of the Back and Nervous Sys- 

 tem, in their Medico-legal and Clinical 

 Aspects. By Herbert W. Page. New 

 York: William Wood & Co. Pp. 157. 



The aim of this book is to give an ac- 

 count of the injuries received in railway and 

 similar accidents that become the subject of 

 medico-legal inquiry. The author has long 

 been a student of this branch, having pub- 

 lished in 1883 a work on Injuries of the 

 Spine and Spinal Cord and Nervous Shock, 

 to which he had given several years of prepa- 

 ration, and having continued his observations 

 since. While injuries of all kinds and de- 

 grees are caused by railway accidents, they 

 do not differ for the most part from those 

 which are seen after other forms of violence. 

 Even the injuries in the back received in 

 railway accidents do not differ from similar 

 injuries received in other ways ; but their fre- 

 quency, and the character they impress on 

 the features of many other forms of injury, 

 demand for them a place by themselves. It 

 is, in fact, a peculiarity of railway accidents 

 that these injuries of the back are nearly al- 

 ways produced, whatever other injuries may 

 occur, and even though there may not be 

 other injury; that the patient is often not 

 aware of them till some time afterward, and 

 that their direct and indirect effects are often 

 widespread and long continued. Vastly more 

 numerous and even more important than 

 these are the cases of "general nervous 

 shock " — an unprecise term applicable rather 

 to the whole of the clinical circumstances of 



