i8o 
Plant Physiology and Ecology. 
more practicable than the one before us : it must set out more 
experiments, and the experiments must he of a simpler and yet 
more rigid nature : there must he less matter in the book, and this 
matter must be set out in a less didactic and more judicial manner. 
As an example of the somewhat dogmatic attitude sometimes 
adopted by the author, we may quote the following:— “It now 
appears to be entirely incorrect to ascribe the presence or absence 
of certain species on limestone soils to the chemical nature of the 
latter” (p. 18). It is interesting to compare this dictum with 
another from Schimper’s Plant Geography (p. 101, English 
edition) “ The ‘ chemical theory ’ has now been indisputably 
maintained, being supported by a correct apprehension of the 
problem, as well as by better material from field observations, by 
analyses of soils, and by cultures.” 
We hope that this rather adverse criticism of Professor 
Clements’ text-book will not be interpreted as an adverse criticism 
of his system of ecology as detailed in his other works and memoirs. 
Professor Clements’ philosophical outlook on ecology as a whole 
and on its relations to other departments of botanical science, his 
persistent advocacy of exact and quantitative work, and of the 
necessity of carrying experimental physiology to the natural plant 
habitat stamp him as one of the greatest ecologists of the age, and 
will leave an impress on ecological thought and ecological methods 
which will be felt for many generations to come. 
C. E. MOSS. 
R. Mauley, Printer, 151, Whitfield Street, London, W, 
