290 
THE PLANT WORLD. 
work have been entirely recast to bring it abreast of the most recent re¬ 
searches, and two new chapters have been added on “ The Geological His¬ 
tory of the Archegoniates,” and on “The Nature of the Alternation of 
Generations.” 
In the latter chapter the author inclines to the antithetic theory of the 
origin of the leafy sporophyte, i. e., that the leafy sporophyte arose “ from 
the zygote of some aquatic algal ancestor,” rather than to the homologous 
theory, that the sporophyte arose as a modification of the gametophyte. 
Several new cuts enhance the value of the illustrations, and the bibliog¬ 
raphy has been entirely revised and increased. The usual high order of 
typographical work of the publishers is maintained throughout. 
C. S. G. 
Research Methods in Ecology. By Frederic Edward Clements, Asso¬ 
ciate Professor of Plant Physiology in the University of Nebraska. Lin¬ 
coln, Neb., The University Publishing Co., 1905. 
This is the first serious attempt in this country at a systematic presenta¬ 
tion of the- problems of plant ecology. The volume is not a text-book, but 
a hand-book for advanced students and investigators, and is an outcome 
of the author’s eight years of research. The point of view is that ecology 
is “ the dominant theme in the study of plants, . . . the central and vital 
part of botany.” The author sanely identifies physiology and ecology, and 
emphasises the fact that both have suffered through their divorce at the 
hands of extreme specialists. 
The first chapter on the needs and essentials of a system, is followed by 
Chapter II. on the “ Habitat,” the construction and use of instruments, 
and methods of habitat investigation. Chapter III. is devoted to the plant, 
with the subtitles, “ Stimulus and Response,” and “ Experimental Evolu¬ 
tion.” The last chapter discusses in detail “ Formation and Experimental 
Vegetation.” A glossary and bibliography complete the work. 
The book will not only help to bring order out of chaos, but will render 
a needed service in placing ecological work on a quantative basis. Stu¬ 
dents and teachers will await with interest the author’s elementary text¬ 
book on the subject, announced in the preface of the present volume. 
C. S. G. 
