July 28, 1905.] 



SCIENCE. 



113 



heritability of species. Such an inference 

 accords with the requirement of the muta- 

 tion theory, but not with the theory which 

 requires perpetual change in all species. 



Certain groups of animals and plants 

 have continued their existence without ma- 

 terial change under very adverse condi- 

 tions of physical environment which were 

 seemingly more favorable for their ex- 

 istence than were those under which they 

 originated. The theory of the origin of 

 species by natural selection is at variance 

 with such facts because it recognizes en- 

 vironing conditions as a constantly domi- 

 nant factor in producing phylogenetic 

 changes, on the one hand, and in preser- 

 ving the integrity of faunaL and floral 

 types, on the other. The mutation theory 

 recognizes the initiative action of an at 

 present unknown determinate natural cause 

 for phylogenetic changes. Environing 

 physical conditions have doubtless been a 

 potent cause in producing variations; and 

 it has doubtless often had a controlling 

 influence upon the destiny of faunas and 

 floras ; but such conditions have not been a 

 direct factor in the origination of species. 



Whatever criticisms may be made of the 

 de Vriesian theory of mutation, the truth 

 will remain that it accords with numerous 

 important facts with which the theory of 

 the origin of species by natural selection is 

 quite inconsistent. Some theory which 

 provides for the sudden, or rapid, origina- 

 tion of species is made necessary by a 

 large array of geological facts, and the 

 mutation theoiy more nearly meets that 

 demand than does any other yet proposed. 

 Charles A. "White, 



Smithsonian Institution, 

 February 20, 1905. 



SCIEXTIFIO BOOKS. 



Introduction a la Geometrie Generale. Par 

 George Lechalas^ Ingenieur en chef des 

 ponts et chaussees. Paris, Gauthier-Villars. 

 1904 Pp. ix + 58. 



The Elements of Plane and Solid Analytical 

 Geometry. By Albert L. Candy, Ph.D., 

 assistant professor of mathematics in the 

 University of ISTebi'aska. Boston, D. C. 

 Heath & Co. 1904. Pp. x + 248. 

 The Elements of Analytic Geometry. By 

 Percey F. Smith, Ph.D., professor of mathe- 

 matics in the Sheffield Scientific School, 

 Yale University, and Arthur S. Gale, 

 Ph.D., instructor in mathematics in Yale 

 College. New York, Ginn & Co. 1905. 

 Pp. xii + 424. 

 An Introductio7i to Projective Geometry and 

 Its Applications. By Arnold Emch, Ph.D., 

 professor of graphics and mathematics in 

 the University of Colorado. New York, 

 John Wiley & Sons. 1905. Pp. vii + 267. 

 Descriptive Geometry for Students of Engi- 

 neering. Second edition. By James A. 

 MoYER, S.B., A.M., instructor in? descriptive 

 geometry in Harvard University. New 

 York, John Wiley & Sons. 1905. Pp. iv + 

 198. 

 The Elements of the Differential and Integral 

 Calculus. By Donald F. Campbell, Ph.D., 

 professor of mathematics. Armour Institute 

 of Technology. New York, The Macmillan 

 Company. 1904. Pp. x + 364. 

 Elements of the Differential and Integral 

 Calculus. By William A. Granville, Ph.D., 

 instructor in the Sheffield Scientific School, 

 Yale University. New York, Ginn & Co. 

 1904. Pp. xiv + 463. 

 The Boston Colloquium: Lectures in Mathe- 

 matics. By Edward B, Van Vleck, Henry 

 S. White and Frederick S. Woods. New 

 York, The Macmillan Company. (For the 

 American Mathematical Society.) 1905. 

 Pp. xH-187. 



Except the last these works are all of them 

 addressed to beginners in their respective sub- 

 jects, and, except the first and last, they are 

 designed for use as text-books in undergrad- 

 uate study. 



The aim of Lechalas's splendid essay is 

 orientation among the fundamental divisions 

 of modern geometry conceived in full gen- 

 erality. Especially intended for such as have 

 not formed a systematic conception of the 

 Euclidean, Lobatchevskian and Riemannian 



