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everywhere the persistent and increasing demand for food must 
be met by the further development of plants suitable to the 
conditions obtaining in any particular country. There are seven 
chapters bearing on general requirements, soil and climate, 
propagation, pollination, fruit preservation, diseases, &c., and a 
glossary. The illustrations include photographic and diagram. 
matic, and especially attractive amongst the latter are the 
diagrams relating to the root system, showing numbers and 
positions of secondary roots, in sections of the soil, 3 ft. wide 
and 7 ft. deep, at various distances of from 4-104 ft. away from 
the tree, and the author concludes that “‘ as a very large propor- 
tion of the roots only spread to a distance of a few feet from the 
stems explains why considerable crops of fruits can be got even 
when the trees are growing very close together, as they usually 
are in date-growing regions, and, as far as the root system is 
concerned, it seems to indicate that if only dates were grown 
a full return would not be got from the land if the trees were 
planted further apart than 20 ft.” This knowledge of the root- 
system is of the utmost importance in a cultivation depending 
almost entirely on irrigation, and it serves a useful purpose also 
in the application of manures. 
The same close attention to detail is obvious throughout the 
whole of the work, which should prove of value to anyone 
interested in the cultivation of this palm. 
College Botany.*--The number of elementary botanical text- 
books published in English must be a high one. Each usually 
has both good and bad points, and the work noticed here is no 
exception to this general rule. The author is professor of Plant 
Pathology and Cecidology at Rutgers College, N.J., and has 
already published a text-book of “‘ Applied Botany.’’ The 
subject, in the work now under notice, is dealt with in such a 
manner as to present as many different phases of botany as 
possible, and to give the student a very general and very broad 
Vi This method of teaching, which has found particular 
favour in America, has many advantages as well as some obvious 
disadvantages. Naturally, when nearly every branch of the 
science is introduced, it is only possible to give outline details 
which sometimes tend to degenerate into dogmatic statements. 
Dr. Cook’s book aims to make a combination of the elementary 
principles of pure and applied science, but the result seems an 
unequal mixture rather than a combination. The most satis- 
factory feature of the book is the reproduction of many excellent 
photographs. The subjects for these are uniformly well selected. 
The outline text-figures are some clear, many indifferent and 
several seriously inaccurate. 
* College Botany, Structure, Physiology a Economies of Plants by 
M. T. Cook, J. B. Lippincott Co., 1920, 12/6 n 
— under the authority of His MAJEstyY’s Y OFFICE 
By Eyr se oa d Spottieweode, Ltd., East t Harding, Street, EC. 4, 
e King’ '3 most Excellent Majesty. 
