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 regar d 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. 111) 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- Bie: instead of accepting it as unhesitatingly as he has done 
on peli7 7 The pre-glacial age of man is not proved by either the 
Cae en n 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 of 
explanations which prejudices the anti-marine theory. The statement 
(p. 186) 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 the elementary principles of the subject are clearly and simply 
taught. 
