REVIEWS. 223 



Species and J^arieties. Their Origin by Mutation. Being Lec- 

 tures Delivered at the University of California. By Hugo 

 deVries, Professor of Botany in the University of Amsterdam. 

 Edited by Daniel Trembly MacDougal, Director Department 

 of Botanical Research, Desert Botanical Laboratory, Carnegie 

 Institution of Washington. Second edition, corrected and 

 revised. Cloth, 8vo, pp. 18 + 847. With a Portrait of the 

 Author. Chicago: The Open Court Publishing Co. Price, 

 $3.00. 1906. 



This most important work of Professor de\>ies in the English 

 presented a no inconsiderable task to the editor, to whom, next 

 to the illustrious author, are thanks due for bringing this work 

 to the Western continent. In the previous volume of this maga- 

 zine, Species and J'arieties, on its first appearance, scarcely a 

 year ago, received a lengthy review which served to indicate very 

 fully to our readers the scope and treatment. These remain 

 unchanged, but there are so very many corrections and emenda- 

 tions that the second edition will needs be in the hand of every 

 student of evolution in its contemporary form. The portrait, 

 which was taken by Dr. W. x-\. Cannon and the reviewer during 

 Professor deWies" visit at the Desert Botanical Laboratory, is, 

 we venture to say, a valuable addition from the human point of 

 view, and will be highly appreciated by the admirers of the 

 author. It is informal in its treatment, but the more shows the 



man's kindlv soul in the spontaneitv of the expression. 



L. 



Hozu Ferns Grow. By Margaret Slosson. With forty-six 

 plates by the author. New York: Henry Holt & Co., 1906. 



As several good books on ferns have appeared within the last 

 few years, one naturally looks for something unusual in Miss 

 Slosson's book, Hoiv Ferns Grow. The author has treated her 

 subject entirely from the standpoint of the development of the 

 fern leaf, showing by detailed description and illustration the 

 successive aspects, in respect to form and venation, taken on by 

 the sporophyte from the youngest stage through to the mature 

 frond, including the modifications which a frond may assume on 



