89 



Elaplioglossum Moort'i (E. G. Britton) Clirist, P.ull. Herb. Boiss. 



II. 3: 148. 1903. 

 Microstaf^liyla Bangii (Clirist) Micron, l^ot. Jahrlj. Mnglcr, 34 : 



539. 1904. 



It is to be liopcd that after this tedious experience the poor 

 fern will rest in peace ! 

 ■>- LuciEN M. Underwood. 



CoLUMHiA University, 

 20 April, 1905. 



^ REVIEWS 



Species and Varieties; Ttieir Origin by Mutation* 



To write two similarly comprehensive works upon the same 

 subject, treated from the same point of view, and not displace the 

 first by the second, nor make the second superfluous is a prob- 

 lem of no small magnitude. In presenting a second work on 

 the mutation theory, Professor Hugo de Vries has solved this 

 problem in a most admirable fashion. 



"Species and Varieties : Their Origin by Mutation " is in no 

 sense a rendering into English, of " Die Mutationstheorie," and 

 is much more valuable in many respects than such translation 

 could be made. The author was doubtless greatly aided in the 

 successful solution of the problem by the difference of oi'igin of 

 the two works. " Die Mutationstheorie " is primai'ily a detailed 

 exposition of the results of research, and was addressed to sci- 

 entists who would appreciate — nay, demand — all the evidence 

 on which are based the far-reaching generalizations involved in 

 the theory of mutation. "Species and Varieties," on the other 

 hand, having grown out of a series of lectures delivered by the 

 author, before the students of a university, assumes in conse- 

 quence a much less rigid scientific aspect, becoming b\- necessit)' 

 intelligible to a wider circle of readers. A technical scientific 

 work may be pored over by those immediately intei-ested in its 

 subject matter until all its important details are comprehended ; 

 but the successful lecturer must make himself instantly intel- 

 hgible to his audience. 



* De Vries, H. Species and Varieties : Their Origin by Mutation. Edited by D. 

 T. MacDougal. 8vo, pp. xii + 847. Chicago : The Open Court Publishing Co. 

 F 1905. 



