216 
NATURE 
[FEBRUARY 17, 1923 

arrangement of auxiliaries, but also conveys much 
useful information regarding their working and main- 
tenance in practice. The subject is treated very 
thoroughly, and contains much that could only be 
found otherwise by searching through periodicals and 
the transactions of engineering societies. 
Heat. By W.J.R. Calvert. Pp. vili+336. (London : 
* Edward Arnold and Co., 1922.) 6s. 
Ir is sometimes difficult to justify the publication of 
a new text-book on a branch of elementary science, 
but Mr. Calvert has been so successful in presenting 
the subject of heat in an attractive and yet scientific 
manner that his book deserves a special word of 
commendation. The first part is intended to cover 
the ground of a general school education, and the 
second part brings the work up to University scholar- 
ship standard. The author realises that the majority 
of those who begin the subject will have little or no 
interest in experimental determinations unless it is 
made clear to them, at the outset, that objectives 
which appear to them reasonable cannot be reached 
without dealing with such measurements. He quotes 
with approval an appropriate sentence from one of 
J. B. Biot’s works—‘‘ Toutes ces choses ne peuvent 
se déterminer sirement que par des mesures précises 
que nous chercherons plus tard; mais auparavant il 
fallait au moins sentir le besoin de les chercher.” 
While practical applications have been emphasised, 
attention has been kept fixed upon the underlying 
principles. In all the experimental work the degree 
of accuracy likely to be attained has been carefully 
considered. In this connexion mention may be made 
of the details and dimensions which have been given 
in the case of many experiments of the laboratory or 
lecture type. We think the author is to be con- 
gratulated on having had the courage, even in so 
elementary a book, to give references to original papers. 
The few readers who look them up will gain a great 
deal, and even those who do not will at least be able 
to use the dates to get some idea of the chronological 
development of the subject. The book is the work 
of a teacher who has given much thought to the treat- 
ment of a familiar subject, and the result of his labours 
forms a valuable addition to the elementary literature 
of an important branch of physics. 
(1) Guide to the University Botanic Garden, Cambridge. 
By H. Gilbert-Carter. Pp. xvi+117+24 plates. 
(Cambridge : At the University Press, 1922.) 3s. 6d. 
net. 
(2) An Alpine ABC and List of Easy Rock Planis. 
Arranged by A. Methuen. Pp. x+35. (London: 
Methuen and Co. Ltd., 1922.) 15. 6d. net. 
(x) IN this attractive little handbook is a systematically 
arranged account of a number of the more interesting 
flowering plants which are cultivated in the University 
of Cambridge Botanic Garden, which should be of 
service to students in the Botany School of the Uni- 
versity. The sequence is the familiar modern German 
one, and under each family is a short description of 
some of the genera and species which are regarded as 
specially worthy of mention. The plates, which are 
good full-page photographic reproductions, add to the 
value and attractiveness of the book. A clear plan of 
NO. 2781, VOL. 111] 

the garden indicating the larger plants with page- 
references to the trees, and an index of the genera and 
species mentioned in the book, enables the student to 
make full use of it. In deference to the oriental 
scholars who have loved and befriended the garden, the 
author has included the eastern names of some of the 
plants, with quotations illustrating the use of these 
names. A historical note gives the date of the founda- 
tion of the Cambridge Garden as 1762, and in 1831 the 
removal to the present site was authorised. 
(2) Mr. Methuen’s notes are for the beginner and the 
amateur. Their purpose is to give a list of the most 
attractive and the most easily grown Alpine flowers 
and to guide in their placing and cultivation. A few 
general rules are given for making a rock garden and 
planting and tending Alpines. The greater part of the 
book is an alphabetical list of the species recommended, 
with indication of the colour of the flower and very 
brief notes on cultivation. The book is the outcome 
of the compiler’s own experience and conveys a good 
deal of useful information in a very small space. 
The Origin and Development of the Nervous System : 
from a Physiological Viewpoint. By Prof. C. M. 
Child. (The University of Chicago Science Series.) 
Pp. xvii+296. (Chicago: The University of Chicago 
Press ; London: The Cambridge University Press, 
1921.) Price 1.75 dollars net. 
In the preface to his book, Prof. Manning Child points 
out that, considered from a physiological viewpoint, 
the origin of the nervous system must be sought in 
conditions present before the appearance of a morpho- 
logical nervous structure. In accordance with this, the 
earlier chapters are devoted to a discussion of the origin 
and nature of the pattern which constitutes the organism 
as a whole, and to a consideration of the experimental 
investigation of some of the physiological conditions 
which antedate the appearance of the nervous system. 
A brief summary is given of the evidence for the 
existence of physiological axial gradients—z.e. graded 
differences in the organism in the rate of the funda- 
mental activities of protoplasm and in the conditions 
associated with these activities—as the essential factors 
in the organismic pattern. An attempt is made to 
show that the nervous system is the physiological and 
morphological expression of the excitation-transmission 
relations, first with respect to the primary physiological 
gradients, and later with respect to the progressive 
dev elopmental complications as they arise. 
Prof. Child admits that with many of his points only 
suggestion, inference, or weighing of probability is at 
present possible. For this reason, and on account of 
the necessary technical detail, the book is more suitable 
for the biologist and physiologist than, as suggested in 
the note on the University of Chicago Science Series, 
to which this volume belongs, for the educated layman. 
The Life of the Weevil. By J. Henri Fabre. 
lated by Alexander Teixeira de Mattos. 
+278. (London: 
1922.) 8s. 6d. net. 
GATHERED together in this volume are the various 
essays on weevils contained in the “ Souvenirs ento- 
mologiques ” of Fabre. Chapters i. and vi.-ix. have 
already appeared wholly or in part in a previous trans- 
lation, as have also chapter v. and parts of chapters vi. 
Trans- 
Pp. viii . 
Hodder and Stoughton, Ltd., 
