NOTES AND LITERATURE. 
GENERAL BIOLOGY. 
Le Dantec’s Treatise on Biology.' — The author of this consid- 
erable volume is well known from a number of general treatises of a 
popular nature all. characterized by an agreeable style, but written 
rather freely, not to say speculatively; that is, not based at every step 
on ascertained fact. His works are what we are accustomed to think 
of as typically French, as opposed to the typically German treatises 
that build up a science out of numberless bricks of recorded observa- 
tions (all fully referred to bibliographically) laid down in orderly 
fashion. 
Le Dantec’s volume is readable but not epoch-making. In places 
it introduces the reader to the very latest ideas— as in the sugges- 
. tive chapter (V) on The Generation with Chromosomes and Sexual 
Parasitism. In other places it seems to bring us back to an earlier 
age, as in the discussion of the formation of species — species being 
defined as groups whose hybrids are sterile. 
The author treats of many things, as a glance at the Table of 
Contents shows: chemical activity in a liquid plasm; assimilation ; 
chemical and histological complexity; sexuality ; sexual parasitism ; 
heredity ; acquired characters; amphimixis; the determination of 
somatic sex; life and death; the formation of species; histological 
differentiation of Metazoa ; parallelism of psychology and physiology ; 
and, lastly, “la liberté et l'égalité" among animals. 
The book is clearly written and will be read by many interested 
in semispeculative biology based, for the most part, on recent knowl- 
edge; but considering its lack of bibliographic citations and its 
somewhat glib treatment of difficult subjects it cannot be considered 
indispensable to the worker. 
C.H D. 
Organic Evolution.?— The author states in his preface that this 
! Le Dantec, Felix. Zyaité de Biologie. Paris. Alcan, 1903. 8vo, 553 PP- 
IOI figs. in text. 15 fran 
* Metcalf, M. M. ye ilies of the Theory of Organic Evolution, with a 
na of some of the Phenomena which it explains. New York. Macmil- 
an Co., 1904. Svo, xxii + 204 pp., 143 pls., and 46 text-figs. 
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