364 BOTANICAL GAZETTE [APRIL 
treatment of the various topics resembles a lecture illustrated by lantern slides; 
this is manifestly conducive to clearness. The entire absence of bibliography 
is a noticeable feature. Probably the introduction of references was not 
regarded as suitable to a textbook, but still is to be deplored, for it detracts from 
the usefulness of the book. This omission might well be remedied in a future 
edition. 
A great deal of stress is laid on the three so-called “canons of comparative 
anatomy,” which are stated to be the doctrines of recapitulation, conservative 
organs, and reversion. In another place the author has _— expressed the 
idea thus: Sian esiopiontes reversion, and retention . . . e the three R’s 
of biological science.”’ In view of the attacks by ia a on a doctrine of 
recapitulation, and of the confident explanation of reversion by thoroughgoing 
Mendelians, it is pleasing to find that a botanist who has made a comprehensive 
study of plant forms not only adheres to these somewhat discredited concepts, 
but accords them fundamental value. It should be noted that JEFFREY does 
not deal with “reversion on crossing,” but reversion as the result of some 
stimulus such as wounding, thus bringing into play a new weapon which is a 
true sort of experimental morphology. 
Turning to the arrangement of the topics, the first 10 chapters deal with 
the various tissue systems, and here naturally the vascular tissues receive the 
major share of attention. Chapters 11 to 16 consider the organs of the plant, 
including interesting chapters on the sporangium, which the author argues is 
an organ sui generis, and on the same footing with root, stem, and leaf. Chap- 
ter 17 lays down the general principles or canons previously mentioned. The 
groups Lycopsida and Pteropsida, first distinguished by the author, are next 
defined, and 11 chapters are devoted to a discussion of the subdivisions of these 
great groups. A valuable chapter on anatomical structure and climatic 
evolution follows. The book closes with a concise description of the technical 
processes involved in preparing woody tissues for study, many of which 
processes have been devised or improved by the author himself. This chapter 
does not contain a description of microscopes and other appliances that nobody 
learns to use from book directions, but proceeds at once to describe the special 
technique for woody material. A perusal of these 25 pages shows why JErEReY 
gets better sections than PENHALLOW obtained by means of a carpenter’s 
plane. 
The book would do good service if it merely served to correct some deep- 
seated fallacies which the author exposes with much skill; for instance, the 
term medullary ray, the so-called primary rays of oak, the origin of the ring 
of vascular bundles found in the stem of Pieris, the supposed primitive nature 
of ca herbaceous type. It is safe to say that this work should prove useful 
alike to the paleontologist, the morphologist, and the general student, and 
should promote the study of plant anatomy in our higher institutions, where the 
subject has suffered from the lack of a work presenting the subject from 4 
modern point of view.—M. A. CHRYSLER. 
