1885.] 
Analyses of Books. 
429 
Text-Book of Structural and Physiological Botany. By Otto 
W. Thoms, Redtor of the High School, Cologne, and Alfred 
W. Bennett, B.Sc., F.L.S., Ledturer on Botany at St. 
Thomas’s Hospital. Fifth Edition, revised and corrected. 
London : Longmans, Green, and Co. 
We have here a most useful Manual, somewhat the worse, how- 
ever, for the very extensive references to examinations, and the 
mode of preparing for them, which are encountered both in the 
“ Preface to the Fifth Edition ” and in the “ Editor’s Preface.” 
All such books, in reality, enforce the painful truth that a thorough 
knowledge of any subjedl and the ability to “ pass ” in it are not 
necessarily identical, the one being able to exist independently 
of the other. But without discussing the evidence on this sub- 
ject, to which the British official mind is obstinately and wilfully 
blind, we must pass on to the work itself. 
The authors, in the very outset, fully recognise the impossi- 
bility of fixing, in any definite manner, a boundary line between 
animals and plants, and the difficulty — to use the mildest term — 
of a natural classification : they then give a history of the 
science, omitting, however, all mention of Lindley, Bentham, 
St. Hilaire, Robert Brown, — who was styled by a German con- 
temporary “ botanicorum facile princeps,” — the two Hookers, 
Asa Gray, Boussingault, and Darwin ! These omissions the 
editor supplies in a footnote, in which room might have been 
found for Ettingshausen, Heer, and Von Muller. 
Passing over the successive chapters on the “ Cell as an Indi- 
vidual,” the “ Cell as a Member of a Group of Similar Cells,” 
the “ Construction of the Plant out of Cells,” and the “ External 
Form of Plants,” we come to a very full and ably written account 
of the “ Life of the Plant.” Here we find it stated that the 
nutrient substances of the plant — in other words, plant-food — are 
“ carbon, oxygen, nitrogen, hydrogen, and sulphur,” to which 
must be added “iron, calcium, potassium, magnesium, and 
phosphorus.” The relative importance ascribed here to these 
elements scarcely agrees with that assigned to them by the 
farmer and the gardener. 
Viola calaniinaria is mentioned as an instance of a plant 
which always contains zinc, and which will grow on zinciferous 
soils only. To the widely diffused presence of copper, e. g., in 
the cacao tree, there is no reference. The manner in which 
plants which live on decaying organic matter absorb their food, 
and are nourished, is pointed out as a problem still unsolved. 
As regards the alleged assimilation of free nitrogen, the authors, 
in common with the leading agricultural chemists of the day, take 
the negative view. 
The fa eft that plants have a true respiration, in which oxygen 
