BOOK EE VIEWS. 



239 



This way of stating the case — viz. of establishing a "Positive " instead 

 of a " Negative " — is decidedly preferable. Sir Oliver thus upholds the 

 conception of " Directivity " which is observable throughout the whole of 

 the organic world. 



" The Vegetation of some disused Quarries : The Conquest of New 

 Ground by Plants." By S. Margerison. 8vo., 52 pp. (Gaskarth, Bradford, 

 1909.) 3s. 



This is an admirable brochure, with thirty-three photographs of 

 different aspects of the quarries, &c. It is an excellent ecological 

 exposition, showing the stages of development, including successive 

 extinctions of the first invaders, to the quasi-permanent establishment 

 now existing. He also shows how the same species, e.g. ling, may assume 

 different habits and also structures according to the spots in which it has 

 found a more or less permanent home. We have often noticed various 

 forms of ling on a fishmonger's stall when grouse is in season. 



" Oecology of Plants. An Introduction to the Study of Plant Com- 

 munities." By Eug. Warming, Ph.D., assisted by M. Vahl, Ph.D. 

 Prepared for publication in English by P. Groom, D.Sc, and Dr. I. B. 

 Balfour, F.R.S.. 8vo., 422 pp. (Clarendon Press, Oxford, 1909.) 8s. 6d, 

 net ; morocco, 10s. net. 



No student of Ecological Botany can neglect this most important work. 

 Since ecology means the application of physiology to plant life, with a 

 complete study of external and internal morphology, with the sole object 

 of discovering the adaptations of every histological detail, even the most 

 minute, to the plant's own requirements, it is at once seen that it covers 

 the whole plant world as it exists in nature. 



This necessitates numerous divisions and subdivisions of the subject. 

 Hence this great volume contains seventeen " sections " embracing 

 thirteen classes [Classes IV. and VIII. seem to be misplaced; pp. ix. x.], 

 and including 100 chapters in all. 



The author begins ' with " Oecological Factors and their Action," 

 requiring twenty-one chapters. "Communal Life" requires five chap- 

 ters. Then follow clusters of chapters on Hydrophytes, Oxylophytes 

 (on acid soils), Halophytes, Lithophytes, Psychrophytes (cold soils), 

 Psammophytes, Eremophytes, Chersophytes (waste lands), Psilophytes, 

 Savannah formations and Sclerophyllous formations (bush and forest), 

 Coniferous formations and Mesophytes. 



The last " section " deals with the Struggle between Plant Com- 

 munities, the hundredth and last chapter being on the " Origin of Species." 

 This chapter has only a little over five pages ; brief paragraphs deal with 

 the views of Darwin, H. de Vries, Vesque, and Lamarck. Darwin has ten 

 lines, terminating with the sentence : — " This explanation [by Natural 

 Selection] has recently been assailed on many sides, and does not now find 

 so many supporters as it had when first promulgated by Darwin." 

 Readers of Dr. Warming's works, such as Lagoa Santa, will be familiar 

 with the fact that he entirely puts "Darwinism " on one side, seeing— as 

 all plant ecologists do — that Darwin's own alternative (first given us in 

 his " Animals and Plants under Domestication," vol. ii., p. 271), that new 



