CURRENT LITERATURE 
BOOK REVIEWS 
An American memorial to Darwin 
The American Association for the Advancement of Science organized at its 
Baltimore meeting last Christmas week a worthy celebration of the centennial of 
Darwin’s birth and the semicentennial of the publication of the Origin of Species, 
part of which consisted of a series of ten addresses by prominent biologists, on 
topics pertinent to the occasion. These addresses have been published as a 
memorial volume, under the title Fijty years of Darwinism.* Of the ten only two 
are by botanists: ‘‘The theory of natural selection from the standpoint of botany,” 
by Joun M. Courter, and “The direct influence of environment,” by D. T. Ma 
Dovcat. Yet all will have a definite interest for any botanist who is alive to the 
questions of evolution. ~ 
Professor CouLTER, after pointing out the indebtedness of botany to DARWIN 
for much besides the theory of natural selection, avows that he speaks not for 
botanists as a whole, but as one “who has had some experience in dealing with 
facts that enter into phylogenies.”” ‘This leads him to set forth some of the diffi- 
culties encountered, such as the origination of those broad characters that dis- 
tinguish great groups, and the so-called “adaptations” which prove to be useless 
or even harmful. The main illustrations are drawn from the gymnosperms, of 
which group he is a master; and the array is certainly formidable. 
Dr. MacDoveat discusses the reaction of organisms when subjected to 
changes in the environment, and the mechanism by which the structural and 
formal alterations are effected. He cites the recent experiments of RIDDLE, GAGE, 
Tower, GacEr, and himself, all of which are well known and have awakened 
the greatest interest. He believes that GAGER’s experiments and his own indicate 
that the p primary effect is wrought upon the chromosomes of the germ cells; a 
conclusion that finds support also from GaTEs’s work on Oenothera and from 
animal cytology.—C. R. B. 
The distinctly zoological addresses are: ‘‘Isolation as a factor in organic 
evolution,” by Davip Starr JorDAN; “The cell in relation to heredity and 
evolution,” by E. B. Witson; “The behavior of unit characters in heredity,” 
by W. E. CasTLE; ‘‘Mutation,” by C. B. DAVENPORT; “Adaptation,” by CARL 
_ 
* Fifty years of Darwinism: modern aspects of evolution. Centennial addresses 
in honor of CHARLES DARWIN before the American Association for the Advancement 
Of Science, Baltimore, Friday, January 1, 1909. 8vo. pp. vit274. pls. 5. fig-1. New 
Yor : Henry Holt & Co. 1909. 00. 
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