242 BOTANICAL GAZETTE [SEPTEMBER 
numerous, reaching 102, of which 29 are Boreales and 73 Aequatoriales. This 
well emphasizes the fact that the genus was very poorly understood. 
The book includes all the features of a complete monograph in the way of 
discussion, keys, descriptions, citations of stations and exsiccatae, etc. The 
discussion includes such subjects as a historical account of the taxonomy of 
the group, an extended analysis of the characters used, the facts of parasitism, 
the origin of the genus, and the range of the species. The numerous plates, 
which are unusually clear photographic reproductions of types and authentic 
specimens, approach in value for reference a set of actual specimens.—J. M. C. 
Soils 
RussELL‘ has written another most interesting little book upon soils. 
His position as director of the famous Rothamsted Experiment Station, which 
has probably contributed more to our knowledge of soils than any other insti- 
tution, and his established ability as a writer and as an authority on soil 
subjects, lead one to expect much from a book written by him, and in the 
present instance this expectation is fully justified. While the book is directly 
practical, dealing with matters that tillers of soils need most to know, it leaves 
the reader with a clear grasp of the main principles established by science and 
practice in this field. Russexi shows a happy breadth of view in treating the 
subject in this as in his earlier works. Some of our American writers on soils 
can profit by his example in this respect. 
The revision of RussELL’s monograph on Soil conditions and plant growth’ 
should have been noted at an earlier date. The first edition has already been 
reviewed in this journal. While the second edition involved no essential 
changes, the third edition has a new chapter on the relationship between the 
micro-organic population of the soil and the growth of plants, also added sec- 
tions in various other chapters of the book, along with other modifications 
that bring the book up to date. The book stands alone as a clear, terse, exact 
statement of the soil conditions in relation to plant growth.— WILLIAM CROCKER. 
MINOR NOTICES 
Microscopy of vegetable foods.—A second edition of WINTON’S volume 
under this title has appeared.?._ The general scope and purpose of this valuable 
4 RUSSELL, BE. J. A student’s book. on soils and manures. pp. ix+206. figs. 3. 
Cambridge Press. 1915 
5’ ———.,, Soil conditions and plant growth. VIII. pp. viiit+s1oo. figs. 9. 34 ed. 
Longmans, Green, & Co. 1915. 
® Bor. Gaz. 55:167-168. 1913. 
7 Winton, ANDREW L., The piste See “i aus arene foods, with special reference 
to the detection of adidterstion and th ith the collaboration 
of Dr. Joser MOELLER and KATE BARBER “Winton. 2d ed. Imp. 8vo. pp. xiv+701- 
Sigs. 635. New York: John Wiley & Sons. 1916. $6.50 
