NATURE 
381 
THURSDAY, AUGUST 26, 1886 
THE PHYSIOLOGY OF PLANTS 
Lectures on the Phystology of Plants. By S. H. Vines, 
M.A., D.Sc., F.R.S. (Cambridge University Press, 
1886.) 
T has already been pointed out in the columns of 
NATuRE that our botanical schools in England are 
at present leading in great measure a parasitic existence 
on those of Germany in respect of the text-books which 
are in common use: translations of the works of Prantl, 
Sachs, and De Bary are in the hands of most of our 
students, while the number of manuals from foreign 
sources will shortly be increased by the publication of 
others which are in active preparation. However greatly 
we may admire the works of the above authors, still it is 
with no small satisfaction that we turn from them to the 
review of a book which we may well regard as the first- 
fruits of a renaissance in this country of the physiological 
branch of the science of botany ; and the more so as the 
production of original text-books may be taken as one 
important indication of activity in the pursuit of the sub- 
ject to which they relate. But while receiving this work 
of Dr. Vines with a hearty welcome, it is to be regretted 
that, as noticed in the preface, a considerable interval of 
time has unavoidably elapsed between the printing of the 
first sheets and the completion of the book: thus one 
great advantage of original production as opposed to 
translation, viz. that of being more nearly up to date, is 
in some measure lost in the present case, and it is to be 
hoped that the book will, as it well deserves, quickly run 
on to a second edition in which this defect may be 
remedied. 
Those who have had the advantage of hearing Dr. 
Vines in the lecture-room would expect from him a clear 
style, and a skilful arrangement of the matter; and these 
are two of the most prominent characteristics of the work 
before us. Its scope is not that of a manual for mere 
beginners : it is rather constructed to meet the require- 
ments of advanced students, and accordingly the author 
is freed from the zwpedimenta of external morphology 
and anatomy, a sufficient knowledge of which he pre- 
sumes to have been acquired from other sources. But 
notwithstanding this presumption, the introductory lec- 
tures open in a manner easily followed by the uninitiated, 
and the whole could be read with advantage by any one 
who has become acquainted with the mere rudiments of 
vegetable anatomy. 
The first three lectures are devoted to the structure and 
properties of the vegetable cell, including the osmotic and 
optical characters of its parts ; this is preparatory to the 
study of the absorption of water, of the substances in 
solution in it, and of gases, which occupies the two follow- 
ing lectures, this subject being followed in fitting sequence 
by a discussion of the movements of water in plants, and 
transpiration. Lecture VIII. is devoted to the con- 
stituents of the food of plants, together with the more 
salient points as regards the functions of the several 
elements, and the sources from which they are obtained ; 
in this, as in other parts of the book, a short historical 
VOL. XXxIV.—No. 878 
sketch is given of the development of knowledge and 
opinion regarding each several function. Then follows 
the subject of “metabolism” in its widest sense, a broad 
distinction being drawn between constructive metabolism, 
or the building up of the organised structures of plants, 
and destructive metabolism, or the conversion of more 
complex substances into others of simpler composition. 
It is in the treatment of the constructive metabolism that 
the most striking novelty will be found by English 
readers, in the introduction of a view regarding the for- 
mation of non-nitrogenous organic substance, which, 
though propounded some years ago in Germany, has now 
we believe, appeared for the first time in an English text- 
book. While allowing that starch is the first w7szble 
product of the constructive processes, the question is 
asked whether the starch which appears in the chloro- 
phyll corpuscles of a green plant under the influence of 
sunlight is dvectly connected with the decomposition of 
carbon dioxide which goes on in them? The answer is 
as follows (p. 145):—“... according to Schmitz and 
Strasburger and in harmony with the older statements of 
Pringsheim, the cell-wall is produced by the actual con- 
version of a layer of protoplasm, and we shall see here- 
after that the same is asserted of the layers of the starch- 
grains found in seeds, tubers, &c. Translating this into 
chemical language we find it to mean that molecules of 
protoplasm may undergo dissociation in such a way as to 
give rise to molecules of carbohydrate among other pro- 
ducts. The conclusion to be drawn is, that the starch 
which is formed in chlorophyll corpuscles under the influ- 
ence of light is also the product of such a dissociation of 
protoplasm.” .. . Both here, and more definitely on 
p- 158, this point is accepted as proved, and is repeatedly 
referred to in the treatment of constructive metabolism. 
But, it will be asked, is it at all admissible thus to “‘ trans- 
late ” microscopical observations into chemical language? 
When it is remembered that we do not yet know the 
constitution of the molecule of protoplasm, that the proto- 
plasm of a living cell is confessedly a most complex 
mixture, and that the observations quoted demand powers 
approaching the limits of microscopic observation, it 
would appear that this “translation” is little more than a 
figure of speech; that the process is probably as Dr. 
Vines describes it many will be found to admit, but it 
cannot be allowed that the evidence adduced by him is 
even a near approach to demonstration. This is not the 
only case of accepting a probability as a proved fact ; 
thus on p. 174 we read :—“ Seedlings, it is well known, 
contain considerable quantities of amides, and the pre- 
sence of these can only be accounted for by regarding 
them as having been derived from the reserve proteids of 
the seed. It is then in the form of amides that nitro- 
genous organic substance is supplied to the seedling.” 
English readers will have become familiar with the 
view of Pfeffer and Draper that it is the yellow rays of 
the spectrum which are most efficient in the process of 
assimilation ; and it will be a new idea to many that the 
balance of experimental evidence is rather in favour of 
the view of Lommel and others, more recently supported 
by the observations of Engelmann, that those rays which 
are absorbed by chlorophyll, viz. the red and violet rays, are 
the chief source of the energy which becomes latent in the 
process of formation of organic substance in green plants. 
Ss 
