NOTES AND LITERATURE. 
GENERAL BIOLOGY. 
Driesch’s Naturbegriffe und Naturteile.' — This introduction to 
the author’s philosophy of nature in a sense completes his systematic 
empirical and theoretical treatment of biology, for the present volume 
is, as he remarks, on the one hand the conclusion of his theoretical 
biological work and on the other the presentation of the results of 
investigations which transcend biology and even natural science 
itself. 
In his earlier books: Die Lokalisation morphogenetischer Vorgänge, 
Analytische Theorie der organischen Entwicklung, Die organischen 
Regulationen, Die * Seele” als elementarer Naturfaktor, Driesch has 
discussed with insight the chief facts and principles of morphogene- 
sis, even to the development of mind, in their relations and their 
theoretical bearings. He now attempts a philosophy of nature, but 
he has not used the title Materphüosophie because he feared that the 
word philosophy might prevent the reading of the book by those for 
whom it was written! Certainly he has ground for his suspicion 
that most biologists have little interest in the concepts of reality, 
constant, energy, measure, substance, entelechy which are analyzed 
in the book. 
The morphology of certain concepts which are of fundamental 
importance in biology as well as in other natural sciences is a brief 
characterization of Naturbegriffe und Naturteile. Those who care to 
know what a philosophically inclined biologist thinks concerning the 
structure and functions of the basal concepts of his science will be 
interested in Driesch's work. 
RM Y. 
De Vries’ Species and Varieties? — The widespread interest 
which has been aroused by the discoveries of Professor de Vries 
makes the publication of this book an important and welcome event. 
! Driesch, T oet lim sae Naturteile. Analytische Untersuchungen 
zur reinen und em Nat "schaft. Leipzig, Englemann, 1904. 8vo, 
viii + 239 
? de Sls Hu ugo. Species and Varieties, their Origin by Mutation, edited by 
D. T. MacDougal. Open Court Pub. Co., Chicago, 1905. 8vo, xviii + 847 pp. 

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