' It is my object to show how variations do arise, viz.: by the 

 plant responding to changed conditions of life; and, secondly, 

 that the altered structures in adaptation to the new environment 

 do become hereditary, if the plants, generation after generation, 

 continue to live long enough in the new surroundings. That is the 

 true and only method of Evolution, (p. 18). 



Numerous examples of this process are given in the 

 Professor's very interesting book. We cannot spare space 

 here to cite them but may direct the attention of readers 

 to an example in the production of parasitism in Passi- 

 flora. (p. 69.) 



Of course the views expressed in this book cut dia- 

 metrically across those of the Weismannites and of the 

 Neo-Darwinians . 



Plantecologists have already abandoned natural selection, in 

 the sense Darwin used it ; but still recognise the usefulness of the 

 term as meaning the survival of the better adapted under the cir- 

 cumstances in the struggle for life. (p. 28.) 



It will be noticed that the Professor postulates what 

 One would imagine all reasonable observers must postu- 

 late, namely the inherent power of the plant or the 

 animal to vary, a postulate which is evaded by many, one 

 might almost say most, of those who write upon the 

 subject, but, all the same, a postulate on which the 

 whole edifice of heredity rests. We are hardly at the 

 beginning of the search for this factor, however much 

 some may try to lead us to believe that all difficulties are 

 solved and all questions cleared up. 



Those who have any such illusions might well be 

 advised to study the work under review. It will suggest 

 some wholesome thoughts and may be commended to 

 the attention of all persons interested in botany or in the 

 larger biological problems. 



B.C.A.W. 



