APRIL 19, 1912] 
which lie at the base of the doctrine of descent. 
But while they present this similarity they 
also differ greatly in their scope and manner 
of presentation, the first covering the broader 
field of the origin and adaptation of species, 
the second reviewing carefully and thoroughly 
our present position with regard to the funda- 
mental facts and theories of heredity, the third 
presenting in a more popular manner the 
principles of Mendelian inheritance, while 
the last is an exposition of a new theory of 
heredity. 
Professor Cuénot’s book is one of the Inter- 
national Scientific Series, and in many ways 
it recalls one of the same series published 
thirty years ago and still a treasury of perti- 
nent facts for the modern zoologist, Semper’s 
“ Animal Life.” It endeavors to present im- 
partially the important facts upon which the 
conclusions of zoological investigation are 
founded, rather than a minute exposition or 
criticism of these conclusions. The first part 
is a brief statement of the growth of the doc- 
trine of transformism and to this succeeds a 
study of the phenomena of reproduction, form 
regulation and correlation, animal behavior 
and sex differentiation, and finally, the dura- 
tion of life of the individual is considered. 
The third part is devoted to the conditions 
under which variation of the individual oc- 
curs, under which heading are considered the 
phenomena of mutation (the Mendelian phe- 
nomena being included under that caption), 
the non-inheritance of acquired characters 
and selection, and then follows a fourth part 
devoted to geographical distribution and the 
faunistic characteristics of the various mi- 
lieux, marine, aquatic and terrestrial. In 
this part one finds brief, interesting discus- 
sions of the planktonie, littoral and bathysinal 
faunas, together with those of brackish and 
supersaline waters, mountain regions and 
caves and, finally, there is a brief discussion 
of commensalism and parasitism. The fifth 
and last part presents, first, a brief statement 
of the doctrine of panspermia maintained by 
Montlivault and Arrhenius, and proceeds with 
a discussion of the origin of species and 
adaptations in which such phenomena as iso- 
SCIENCE 
625 
lation, parallelism, polymorphism, regression, 
protective and warning coloration and mim- 
iery are illustrated by well-chosen examples. 
A brief exposition of the views of Lamarck, 
Darwin, Eimer, Weismann and the post-Dar- 
winian schools rounds out a satisfactory con- 
crete exposition of what may be termed the 
principles of general zoology. Notwithstand- 
ing the conciseness necessary in a work cov- 
ering so wide a territory the book is most 
readable and interesting, and, with its extraor- 
dinary wealth of well-chosen examples and 
its abundant illustrations, will prove a boon 
both to the teacher and the student of general 
zoology. 
Haecker’s “ Allgemeine Vererbungslehre ” 
has more of an academic character, being the 
outcome of lectures delivered by the author in 
past years at Stuttgart, Hohenheim and 
Halle, and will be welcomed by professional 
zoologists as a thorough scientific exposition 
of our present knowledge of the underlying 
principles and laws of inheritance. Starting 
with a brief historical section, in which 
Galton’s law is discussed, the morphological 
bases of heredity are considered with a 
thoroughness and clearness that are admir- 
able, the author’s experience with cytological 
phenomena as seen in copepodan germ cells 
rendering him especially at home in this part 
of his subject. Of especial interest are the 
discussions of heterotypic mitoses and hetero- 
chromosomes and of the significance of the 
number of chromosomes. The third section 
is of a more theoretical nature, being devoted 
to a review of Weismann’s hypotheses and 
Hertwig’s theory of biogenesis. 
The fourth section is a return to the de- 
seriptive side of the subject, the phenomena 
of Mendelian inheritance being under consid- 
eration, and receiving a remarkably clear pre- 
sentation, excellently illustrated. In the con 
cluding section theoretical considerations, 
such as the individuality of the chromosomes, 
the reduction division and the determination 
of sex are again prominent, and the last chap- 
ter is devoted to the discussion of a Kern- 
plasma theory of heredity to replace the 
chromosome theory. 
