NATURE 
393 
THURSDAY, JUNE 20; 1912: 
INTRODUCTIONS TO BIOLOGY. 
(1) Outlines of Evolutionary Biology. By Prof. 
Arthur Dendy, F.R.S. Pp. xiv+454. (Lon- 
don: Constable and Co., Ltd., 1912.) Price 
12s. 6d. net. 
(2) Lebensweise und Organisation: Eine Ein- 
fiihrung in die Biologie der wirbellosen Tiere. 
By Prof. P. Deegener. Pp. x+288. (Leipzig 
-id Berlin: B. G. Teubner, 1912.) Price 
5 marks. 
(3) Einfiihrung in die Biologie. By Prof. Otto 
Maas and Dr. Otto Renner.. Pp. ix+394. 
(Miinchen and Berlin: R. Oldenbourg, 1912.) 
Price 8 marks. 
(4) The Life of the Plant. By Prof. C. A. Timiri- 
azeff. Translated from the revised and corrected 
Seventh Russian Edition by Miss Anna 
Cheéréméteff. Pp. xvit+355. (London: Long- 
mans, Green and Co., 1912.) Price 7s. 6d. net. 
(1) ROF. DENDY regrets that so little 
encouragement is given in this country 
to the study of biology in the strict sense—the 
study of the general principles underlying the 
special sciences of botany, zoology, protistology, 
and the like. We fear that there is too much 
truth in this, for while there may be a considerable 
leaven of general ideas in the course the medical 
student gets, whether it be a little botany and a 
little zoology, or the conjoint “bean and dogfish ”’ 
scheme, it must be confessed that he has little 
opportunity for ‘‘a philosophical treatment of the 
subject.” It is customary to say that he is not 
at the age and stage to appreciate it, but this is 
probably in the main an erroneous assumption, 
and we welcome Prof. Dendy’s book because it 
supplies an effective introduction to biological 
conceptions without adding greatly to the burden 
of facts which the student is expected to bear 
about with him for a season. In reality, of course, 
it gives the burden a balance, which lightens it. 
But besides medical students there is another 
constituency—and a rapidly increasing one—of 
men and women who wish to think biologically, 
because they have already learned to think clearly. 
They wish in particular to understand the bearing 
of biological conclusions upon human problems, 
and they are aware that the only way to get a 
grip of general principles is to submit to discipline 
in the concrete. Regular laboratory work is out 
of the question, and many remain platitudinarian. 
But, as Prof. Dendy points out, “We are apt to 
forget that in reality we all of us spend our lives 
in a biological laboratory, where we are sur- 
rounded by living organisms which we can hardly 
NO. 2225, voL. 89] 
avoid studying. In this way we learn much of 
the nature of living things, and are to some extent 
prepared for the study of biological principles.” 
To serious students who wish to understand the 
biological laboratory in which they live, Prof. 
Dendy’s book will be a trustworthy and stimu- 
lating guide. We wish that he had been able to 
do even more in the way of indicating the 
biological significance of our familiar animate 
environment, but we cannot suggest what might 
be omitted to make room for this. 
The first part of the book deals with the essen- 
tial functions of the living body, the unicellular 
grade of organisation, the transition to the multi- 
cellular grade, the meaning of differentiation, and 
the cell theory. The second part deals with the 
evolution of sex and with reproduction, the third 
with variation and heredity, the fourth with the 
theory and evidences of organic evolution and 
with adaptations in plants and animals. The fifth 
part discusses the factors of organic evolution. 
It is all admirable; indeed, we do not know how 
it could be done better. It is packed with interest- 
ing material, old and new; the style is clear and 
vivid, yet the reader is continually being pulled 
up to think; there is a pleasant absence of 
dogmatism in regard to debated questions; there 
are numerous effective illustrations, many of which 
are new. The good qualities of the book stand 
out prominently in the chapter on the inheritance 
of acquired characters, in which the author admits 
the difficulty of saying yea or nay, warns the 
student against dogmatism, sets a good example 
of unbiassed examination of the evidence, con- 
cludes that “characters which are due to the con- 
tinued action of some external stimulus, extending 
perhaps over many generations, in the long run 
become so firmly impressed upon the organism 
that they affect the germ-cells as well as the 
somatic cells, and thus become truly blastogenic,” 
and then suggests an hypothesis—not perhaps to 
be pressed just now—that modifications of somatic 
cells may, by altering the character of the vibra- 
tions in the determinants of their own nuclei, affect 
the corresponding determinants in the distant 
germ-cells in a similar manner, in some way 
analogous to wireless telegraphy. 
(2) The aim of Prof. Deegener’s book is also 
to introduce the serious student to biological con- 
ceptions; the method is to take a survey of the 
invertebrates, using the diverse types in illustra- 
tion of particular points. Thus the author uses 
the myonemes of Stentor and the like to illustrate 
division of labour within the cell, Volvox to throw 
light on the beginning of sexual reproduction, 
Hydra as a peg for a discussion of regeneration, 
the Trematodes as instances of adaptation to para- 
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