206 THE JOURNAL OF BOTANY 
students who require a thorough grounding in eet Sateen of 
histological construction and its relation to the vital needs of 
tive details unimportant to any but the specialist. For instance, 
ung pharmacist who aims at something more than 
the coreg its hints on the most suitable objects me eeeory 
investigation at the end of each chapter, and its 
technique, ph micro-chemistry, and on detection of Sh ae 
in food and drugs, an admirable guide to the whole subject. 
a noe academic botanica prety ae Prof. Stevens’s 
wo Bri eh or does it ey to be, gaat comprehensive 
Teh ree of accuracy in gt es n a succession of 
aioe: ie deals with The Plant Cell, Differentiation of the 
Tissues, Secondary Increase in Thic Protection fro 
juries and Loss of Water, The Plant Skeleton, The Absorption of 
ater als, Circulation of W d Soil Solutes, 
Never for a intact does Prof. Sinn 
] eal pharmacognos 
allow the details of structure to become divorced in the reader’s 
the 
mind from fundamental See singsal processes going on in 
the plant. A Megs 4; and original feature of the book is. the 
Serta of numerous diagrams illustrating the relations of the 
different tissues one ia another, and the course of water and food- 
substances through. the plant-body. These will be of very great 
assistance to the student in _— the structure of the plant as: 
a delicately adjusted machin 
ere is not much that. can be adversely criticized. The 
fundamental importance of enzymes as revealed by modern work 
is scarcely sufficiently insisted on in dealing with the activities of 
blemishes.. Figure 11, for instance, mewhat misleading — 
gives 
idea of the relation of the leaf-trace to ‘as Jebliiian system of the 
- stem. The relation of the true cambium to the zone of undiffer 
entiated parenchyma badkitacts the xylem and phloem of t the: 
primary bundle is not’ well brought out. The radial seriation of 
t 
