256 SCIENCE PROGRESS. 



and refusing to treat seriously the proposition that all the 

 poplars in France are only parts of an individual. Chapter 

 II. is concerned chiefly with a discussion of the question 

 whether continued vegetative propagation is injurious to 

 the constitution of plants like the Banana, Potato, Poplars, 

 Fruit-trees, and numerous other plants — wild as well as 

 cultivated — which are rarely or never grown from seed. 

 His views are similar to those of a recent American author 

 who has written clearly and suggestively on this subject/ 

 and may be shortly put as summing up against the view 

 that varieties or species show signs of deterioration or 

 dying out from this cause. 



In the third chapter Mobius discusses the conditions on 

 which the flowering of plants depends. The influence 

 of light, temperature, moisture, and nutrition, etc., are 

 successively examined, but although the facts collected are 

 interesting one feels dissatisfied with the results, partly 

 owing to the cause already mentioned — that experiments in 

 this domain involve such complexities that one is never 

 sure that the response is to a given factor of the environ- 

 nient — and partly because the whole work seems hurriedly 

 written." Moreover, in this chapter the author gives the 

 only experiments quoted which he has himself performed, 

 and they are distinctly unsatisfactory. 



In chapter four, the relations between bud-propagation 

 and reproduction by seeds is discussed, with much reference 

 to Darwin's celebrated chapter in his " Variation of Animals 

 and Plants under Domestication ". 



By far the most interesting part of the book to most 

 botanists will be the last chapter, in which the author gives 

 a summary of the origin and significance of sexual repro- 



iT. H. Bailey, T/ie Survival of the Unlike, 1896. 



- This latter conclusion is borne out by the misprints which are too 

 common (and evidently not all printer's errors) here and elsewhere in the 

 book, e.g., " Do the Musa show any signs of deteriation " (a quotation on 

 p. 34), Biilhen for Blilheti (p. 84), Laryx for Larix (p. 88). Two errors 

 in a quotation on p. no. Ramoicutiis (p. 138). Musa sapientium instead 

 of sapientum repeatedly, and also Hit/ianthallia for Himanthalia several 

 times. 



