Reviews. 
77 
REVIEWS. 
VEGETABLE TERATOLOGY. 
The Principles of Plant Teratology. By Wilson Crosfield 
WoRDSELL, F.L.S. Vol. i. London (Ray Society) ; Dulau & Co., 1915. 
Pp. xxvi. + 270. Pits, i.-xxv. Price, 25s. net. 
The greater part of half a century has elapsed since the Ray Society pub- 
lished Dr. Maxwell Masters' well-known volume on Vegetable Teratology, 
This pioneer work has long been out of print, and for that reason, as well as 
because in the interval large additions have been made to our knowledge of 
teratological phenomena amongst plants, Mr. Wordsell's new and enlarged 
work is to be welcomed. The present volume deals with the cryptogams and 
with the root, stem, and leaf of phanerogams. A second volume, in which the 
flower is to be dealt with, is promised to complete the work. 
The work is presented as a contribution towards a knowledge of the evolu- 
tionary origin of plant-organs, and not merely as a descriptive catalogue of 
plant monstrosities; and in his introduction the author emphasises the im- 
portance of a correct knowledge of abnormal structures as an aid in the inter- 
pretation of problems of normal plant morphology. He insists on the insuffi- 
ciency of mere physics and chemistry as causative agents in morphological 
development, and he therefore calls in the aid of a regulative vital force as a 
necessary factor in this connection. 
In dealing with the cryptogams the abnormalities are discussed under such 
headings as "proliferation," "dichotomy," " fasciation, " etc., without hav- 
ing special regard to the particular organs of the plants in which they occur. 
In the case of the phanerogams, however, the various classes of abnormalities 
are dealt with separately as they occur in the root, stem, and leaf respectively. 
It is impossible in a brief notice of the book to do more than give a general 
idea of its varied contents, but the following may serve to illustrate the 
author's method of treatment of his subject. In dealing with the causes of 
that rather common form of abnormality known as "fasciation," he discusses 
first the " fusion theory " and then the "expansion theory." Finding neither 
of these entirely to his satisfaction, he upholds the "pleiotomy theory," and 
observes, "Fasciation is the imperfect formation of a number of offspring 
(multiplets) by partition, and is a result of the compromise established be- 
tween the forces makmg for unity and fission respectively." 
The book is illustrated by a number of text figures, not of strikingly artistic 
merit, as well as by twenty-five plates. It is well indexed, possesses a useful 
glossary of terras, and its value is much enhanced by the copious bibliographi- 
cal references supplied at the ends of its principal sections. Its price is un- 
fortunately high. 
G. H. P. 
