REVIEWS 335 



participation in a discussion of modern evolutionary questions. For life is short 

 and a book in German is apt to be long, and we take it that Prof. De Vries had at 

 least considerable opportunity of making his meaning clear in Species and Varieties^ 

 their Origiti by Mutation^ which appeared in English in 1905. On the other hand, 

 the subject is one of extreme difficulty, the author has much that is new to 

 contribute, he uses some terms in a sense peculiarly his own, so that it is of great 

 advantage to have the detailed evidence before us. In any case, the evidence 

 collected by De Vries up to 1901, bearing on the question of the origin of species 

 and varieties by mutation, is now for the first time available to the student of 

 evolution who cannot or will not read German. 



The book before us is certainly an addition to the not very crowded shelf of 

 great books on organic evolution, and we envy those who make its first acquaint- 

 ance in its English dress. They will be interested in the story of the author's 

 experiments, the inferences that he has drawn from them and from the behaviour 

 of Oenothera lamarckiana in particular, his divergence from Darwin and the 

 selectionists, and his fundamental contrast (so difficult, it seems to us, to work 

 out) between mutations and fluctuations. Every here and there we must confess 

 that we find some special point that we had overlooked before — for instance, the 

 author's obiter dictum that it may be change of environment that pulls the trigger 

 of mutations, for which " we can as yet assign no cause," which emerge from the 

 arcana of the germ-plasm, seemingly independent of the environment. We may 

 briefly refer to what the author singles out as the most important results of 

 the experimental work in which he has taken such a large share. He declares 

 that the principle of unit-characters " has gained almost universal acceptance, though 

 there are still some authors, especially among zoologists, who are opposed to it." 

 A clearer understanding of the processes of selection in plant-breeding leads 

 to a recognition of the elementary species as the real material for artificial and 

 natural selection, a view which has been "corroborated in convincing manner 

 by the work of Nilsson and of Korschinsky." Secondly, De Vries points to his 

 detailed experimental evidence, now made more available by the translation before 

 us. He refers especially to "the observed origin of Oenothera gigas^ which appeared 

 suddenly in my cultures in the year 1895, ^^^d possessed, at its first origin, all the 

 attributes of anew species, including constancy and even a double number of chromo- 

 somes in its nuclei." Thirdly, he refers to " the new light thrown by the principle 

 of the unit-characters on the work of Mendel, neglected up to that time." Nowa- 

 days it seems rather the other way round, that the work of Mendelians throws light 

 on the idea of unit-characters. "The work of Bateson and of his school, of 

 Cuenot, Webber and many others, but above all that of Davenport, have since 

 brought the principle of unit-characters to its now prominent rank in the study of 

 hybridization." J. Arthur Thomson. 



Keports on the Geophysics, Geology, Zoology, and Botany of the Islands 

 lying to the South of New Zealand, based mainly on Observations and 

 Collections made during an Expedition in the Government steamer 

 Hinemoa (Captain J. Bellows), in November 1907. Edited by Charles 

 Chilton, M.A., D.Sc. In two volumes. [Vol i. pp. xxxv -H 388 ; vol. ii. 

 pp. 389-848.] (Wellington, N.Z. Published by the Philosophic Institute 

 of Canterbury, 1909. Price 42^. net.) 



Lying to the south and south and south-east of New Zealand there are scattered 

 several small, for the most part uninhabited, islands which, in the old days of the 



