214 
NATURE 
[May 2, 1912 
being inverted. On p. 214 the name “Alg@” 
should be in clarendon type so as to be in con- 
formity with the other groups, such as fungi, 
lichens, &c.; and on p, 218 the spore-bearing 
plants with stem and leaves might be well termed 
Archegoniates, but not “ Bryophyta.” 
The translators are to be congratulated upon 
putting before the English public a most interest- 
ing elementary work on botany, and one which 
cannot fail to be stimulating to the junior 
student. 
The second work treats of the flowers of twenty- 
five species of British plants, each one of which 
is illustrated by a photograph in colours and 
small text-illustrations of various parts of the 
flower. The text is very well written, and is full 
of folk-lore and legends concerning the plants 
dealt with. One useful feature of the book 1s 
the description of the pollination of the various 
flowers, but it must be mentioned that through- 
out the book the author makes the technical error 
of using the word “fertilisation” for pollination. 
This is the only flaw in a book which is an ex- 
cellent one of its kind, and which would make a 
charming gift to any person interested in wild 
flowers. The majority of the plates are good, 
the best of them being the illustrations of Arum 
maculatum, the crab-apple, the cowslip, and the 
toothwort. The colouring of the gorse, and 
especially that of Orchis mascula, is scarcely 
true to life. 
In the third publication there are ten chapters 
dealing with “Plant Life and Evolution.” All 
are good, from the admirable introductory 
chapter to the concluding one on the ‘Origin of 
Species.” The chapters dealing with the factors 
in evolution, with environment and adaptation, 
are excellent, but perhaps the best section of the 
book is that on the “Problems of Plant Distribu- 
tion.” Prof. Campbell’s account of the “Origin 
of Land-plants ” is just such a brief summary as 
so many students require, but it should be re- 
marked that in it the author inclines to Bower’s 
antithetic view of alternation of generations. The 
chapter on “Seed-plants” is a good résumé on 
the evolution of Gymnosperms, 
There is some doubt whether diatoms are so 
recent in origin as suggested by the author, and 
not everyone would agree that Euglena 
structurally more like an animal than a plant.’’ 
The book must be considered as a_ valuable 
addition to the smaller text-books on botany, 
and exactly suited to the student who has 
mastered the elements of botany, and requires an 
insight into the principles of evolution. 
The intermediate text-book by Mr. Evans is an 
ccs 
1S 
attempt by the author to condense a rather large 
NO. 2218, VOL. 89] 
amount of fact into a relatively small space. It 
is pervaded throughout by a looseness of ex- 
pression, and the mistakes in the earlier part of 
the book are almost too numerous to mention. 
Some of these errors are serious from the point 
of view of the student. The treatment of the 
Spermatophytes is much better, but even here 
the author’s account of photosynthesis would be 
much improved by careful revision. On the 
whole, one could not recommend this book to an 
“Tntermediate”’ student unless considerably 
revised. 
OUR BOOKSHELF. 
Hydro-Electric Practice. A Practical Manual of 
the Development of Water Power, its Con- 
version to Electric Energy, and its Distant 
Transmission. By H. A. E. C. von Schon. 
Second edition. Pp. xvii+383. (Philadelphia 
and London: J. B. Lippincott Company, 1911.) 
Price 25s. net. 
WE heartily welcome this second edition of Mr. 
von Schon’s admirable treatise on ‘‘ Hydro- 
I:lectric Practice.” Although only four years. 
have elapsed since the first edition appeared, 
general interest in hydro-electric schemes has. 
greatly increased, partly, no doubt, due to the 
way in which the public imagination has been 
fired by the possibilities of electrochemical and. 
electrometallurgical processes, particularly as. 
applied to the manufacture of iron and steel, and 
to the fixation of atmospheric nitrogen. It is on. 
this, if on no other, account to be regretted that 
the book deals solely with conditions as they exist 
in America, and that no illustrations are drawn 
from the vast water-power schemes now in course 
of construction or operation in Norway, for 
example. 
As in the first edition, the book consists. 
essentially of two portions, the first a general’ 
survey of hydro-electric projects and possibilities, 
intended for the investor and capitalist rather 
than for the engineer, and the second portion a 
really valuable account of the design and con- 
struction of a water-power equipment which will 
be indispensable to engineers actually engaged in 
constructional work. 
The sections dealing with the electrical equip- 
ment are somewhat meagre, and they should at 
least have been supplemented by a full biblio- 
graphy of the extensive existing literature cover- 
ing this branch of the subject. 
It is a pity that the author should have dis 
figured his otherwise perfectly lucid descriptions 
by writing such a sentence as is to be found on 
p- 25, in which the terms ‘‘energy” and’ 
‘‘power ’’ are used indiscriminately in hopeless 
confusion. Again, why ‘‘ cubic second feet ”’ in- 
stead of ‘“‘ cubic feet per second’’? These may 
| seem, and no doubt are, small points, but a 
writer who uses scientific terms loosely is bound’ 
to arouse suspicion; in this instance at least 
