Current Literature 25 



tations must be in part the result of function, and its study needs 

 knowledge of physiology as well as physiography, geography, 

 etc., being in turn a handmaiden to these, so that Schimper was 

 induced to entitle his book: Pflanzengeographie auf physiolog- 

 ischer Grinidlage. The book is so replete with interest that only 

 an intimate study will bring satisfaction, the reviewer being re- 

 strained to merely giving glimpses into the contents. 



There are onl}^ four chapters, headed : the foundation of 

 ecology ; the habitat ; the plant ; the formation. The first 

 chapter gives on 17 pages a brief history of the development of 

 the science, which culminates in the author's study of habitats 

 by exact methods and measuring physical factors by means of 

 instruments, which are further on fully described. The rela- 

 tionship of ecology to other branches of science and to arts is 

 discussed at length. Referring to forestry, it is pointed out that 

 a full knowledge of the character and laws of succession will 

 prove of value in reforestation, and that the substitution of de- 

 termining with precision the physical nature of the habitat for 

 the superficial study of forest formation and guessing at the 

 physical causes which control both structure and development, 

 will be the greatest service of ecology to forestry ; this especially 

 in plantings in non-forested regions where it has so far been im- 

 possible to estimate the chances of success. 



The second chapter discusses on 8 1 pages the methods study- 

 ing the habitat, i.e., "the sum of all the forces or factors present 

 in a given area." 



These factors are classified into biotic (animals and plants) 

 and physical (climate and soil) ; the latter are discussed at length 

 namely water contents and humidity, light, temperature, pre- 

 cipitation, wind, soil, and the physiographic factors, altitude, 

 slope, exposure. The effect of each on plant-life is described, 

 as well as the instruments for studying them, the methods of 

 procedure in the study and of recording results. Sixty pages 

 are devoted to the Plant, the nature and kinds of stimuli and 

 the nature of response, adjustments and adaptations to water 

 (hydroharmose) and to light (photoharmose), and methods of 

 experimental evolution. The Plant Formation receives the 

 lion's share with 153 pages. 



The use of ' ' quadrats ' ' and ' ' transects ' ' of various descrip- 

 tion, or what foresters would call sample areas, to study com- 



