and their origin. This is followed by the discussion of the 
factors involved in rock disintegration and the accumulation of 
finely divided material into which organic remains are incor- 
porated. An exposition of the geological classification of soils and 
.climate, as affecting soil development is presented. Considera- 
tion is then given to the physical properties of soils as influenced 
by the size and shape of soil particles and the structure of soil 
grains. 
The relations of soils to air, water and heat, the nature of the 
soil solution, the solution of plant nutrients and factors which 
affect the processes, the nature and meaning of soil acidity and 
alkalinity and the significance of alkali are discussed effectively. 
Some space is devoted to plant physiological relations, the nature 
and activities of soil microorganisms, the circulation of plant 
food, the effect of fertilizers and soil amendments; and, finally, 
tillage, drainage and irrigation are considered. 
Although this is not a book of a popular character and calls 
for some knowledge of chemistry, physics and microbiology there 
is much in it of great value to the seriously minded horticultur- 
ist who is grounded in these subjects. Unquestionably it is the 
best available textbook on soils and soil fertility and contains 
a mass of information which makes it a reference as well as 
textbook. J. G. Lipman. 
Trees, Shrubs, Vines and Herbaceous Perennials. By John 
Kirkegaard, assisted by Dr. H. T. Fernald and Prof. E. A. White. 
Published by Williams Bookstore Company, Williams Building, 
323-325 Washington Street, Boston, Mass. Promoted by The 
Gardener's Chronicle. 
A practical handbook consisting of four plans for gardens, 
an alphabetical description and classification of trees, shrubs 
and vines covering 213 pages, short articles on planting, culture 
and various pests, some lists of suitable plants for various places 
and some sixty photographs. 
The latter are placed together and we are told that they have 
been selected "to illustrate many of the uncommon or partially 
known species and varieties," not for the purpose of showing 
"merely pretty pictures." They hardly live up to their purpose 
— Aquilegias, Veronica, Tulips, Berberis Thunbergii, Clematis 
paniculata, German Iris and Hydrangeas are not exactly novel- 
ties. They could well be omitted, making the handbook lighter 
and easier to use. The lists are practical and concise and should 
be useful once the reader has mastered the thirteen alphabetical 
abbreviations that are used — turning back for information is 
annoying. A small Glossary is excellent and helpful to the 
amateur. The plans are interesting but not unusual and one 
regrets the use of Crimson Rambler at any time — as well as 
"100 Babj r Ramblers" in the Rose plan. The articles on Pests 
37 
