— 
Feb. 24, 1870| 
gathering of the natural produce of the earth, but has 
become, more thoroughly than elsewhere, the art of manu- 
facturing food, there should not be an activity in the 
teaching and prosecution of agricultural science propor- 
tionate to that existing where agriculture is in a more 
primitive state. 
However, a beginning is being made in this direction, 
and it is to aid students in acquiring a knowledge, both 
technical and scientific, of the less obvious aspects of 
plant-life, that the volume mentioned above has been 
written. The classification of the subjects treated of is 
Fig. 3.—Section of outer cells of an oat grain; @ and ¢ containing chiefly 
caseine, and 4 starch granules. 
adapted both to this object and to the wants of the lecture- 
room, while the illustrations of particular phenomena are 
in all cases chosen with reference to agricultural 
practice. 
The first division is devoted to the chemical composi- 
tion of the plant. Here the elementary substances of 
which plant organs and their materials consist are briefly 
described, chemical force is defined and the technical lan- 
guage of chemistry explained ; then follows an account of 
the characters and composition of substances which are 
common products of vegetation in all its forms, of others 
which are more or less peculiar to certain plants ; and lastly, 
the important subject of the ash of plants is discussed 
in regard to its general and special character, the extent 
to which its constituent parts are accidental or essential, 
and the functions it or its several parts may perform in 
the growth and development of the plant. 
The special organized forms in which the common 
materials of plants present themselves are well illustrated 
a 6 ce ad 
Fig. 4.—Forms of various albuminoid grains ; a from vetch seed ; 4 from 
the castor bean ; c from flax seed ; d from Myrica Cerifera ; and e from 
the aril of the nutmeg. 
by numerous woodcuts, of which figs. 1, 2, 3, and 4 will 
serve as examples. 
Copious references to special investigations and 
monographs are given throughout this division of the 
book; but unless we have credit for doing even less than 
has been done in this country, it would seem that the 
references are too exclusively to German authorities. 
Only in one instance are the elaborate observations of 
NATURE 
427 
Lawes and Gilbert mentioned (p. 316), and French 
experimenters are also but rarely referred to. 
One excellent feature of this division consists in the 
tabulated statements of the amounts of particular con- 
stituents contained in various plants, in a form that will 
be not only instructive to the student, but very useful for 
reference. 
The second division deals with the structure of the 
plant, the offices of its organs, the nature of the plant 
cell, the organs of nutrition and of reproduction, with their 
several functions. 
The third division treats generally of the life of the 
Fig. 5.—Young wheat plant with earth adhering to roots at ¢, while the root 
tips W, and the other parts of the primary roots e¢, and of the secondary 
roots x are bare. JS is the seed and 4 the blade. 
plant, describes how the seed germinates, what is the food 
of plants, how it is taken up, the nature and the motion 
of the sap and the various forces by which this is 
influenced, the mode of reproduction, and, lastly, the 
death of the plant. 
Then follows an appendix, with copious tables of the 
composition of agricultural plants and products, cattle 
feeding materials, &c., which cannot fail to be useful. 
