276 NATURAL SCIENCE [October 



in the preparation of a future edition is greater uniformity of 

 standard, and the reduction in number of needless technical terms. 

 In regard to the latter, the editor even proposes new terms in the 

 course of the book, describing some springs as " transtatic." Even if 

 the term were useful, its first publication in a shilling text-book 

 could hardly be commended. The restriction of "isothermal" to mean 

 annual temperature is neither usual nor convenient. There are still 

 many points in which revision is necessary ; Africa is not now 

 regarded as exempt from earthquakes (as stated on p. 154); it is too 

 late to say that the cause of the rising of the Nile is covered by 

 "much obscurity," or to affirm that glacier ice is "not plastic." The 

 geological classification of lakes into two divisions only (p. Ill) is 

 quite inadequate, while it is only burdening a student with useless 

 definitions to separate rivers into oceanic and continental, according 

 to whether they flow into the ocean or not. The appendix on the, 

 geographical distribution of animals could do with thorough revision : 

 Colubus is not a " tail-less ape " (p. 209) ; and to say that the long- 

 tailed manis and the ground-pig are "almost exclusively African" is 

 an error from excess of caution ; the python is not only found in the 

 Indian region ; Lepidosiren is not a reptile, and it is not excusable 

 now to include the crocodile among the lizards. 



Mr W. Jerome Harrison is a very experienced science teacher, a 

 practical geologist, and has always shown himself a painstaking and 

 accurate worker ; hence it is not surprising that his " Text Book of 

 Geology " has reached a fourth edition. It now appears so much 

 enlarged and revised that it is practically a new book. The syllabus 

 for geology issued by the Science and Art Department is reprinted at 

 the end, accompanied by the questions set at the May examinations 

 for the past eight years. This fact suggests the class of students the 

 author wished to help ; and for the elementary stage of that examina- 

 tion we know of no better class-book. The book is, as a rule, reliable 

 and well up-to-date ; but we notice a few old figures that might have 

 been omitted, and a few points that might be revised. # The author 

 might have added the supposed land plant Berwynia to the list of his 

 pseudo-fossils, instead of accepting it as unhesitatingly as he has done 

 on p. 177. The pre-glacial age of man is not proved by either the 

 Cae Grwyn Caves or the Brandon implements. The explanation of the 

 Moel Tryfaen shells as "pushed up to their present heights in front 

 of" a glacier [the italics are Mr Harrison's] is one of the type (if 

 explanations which prejudices the anti-marine theory. The statement 

 (p. 180) that crinoids " are dying out, a few specimens only lingering 

 at the bottom of the deep seas," is a survival from twenty years ago, 

 which still lingers in many elementary works. Another common 

 mistake is regarding the Neocomian as the equivalent of the whole of 

 the Lower Cretaceous. The illustrations are numerous and good, and we 

 hope the book will soon reach a fifth edition. 



The fourth and fifth books are not quite within our range; but 

 geographers and geologists occasionally have to deal with questions to 

 which some knowledge of the mechanics of fluids is essential. We 

 therefore need make no apology for calling attention to works in 

 which tin' elemental)' principles of the subject are clearly and simply 

 taught. 



