171 



sive knowledge of meteorology, physics, chemistry, geology, 

 botany, and sociology, and their intimate relations to the main 

 topic. At the same time it is written in a simple and attractive 

 style, and is as free as possible from technicalities. The type, 

 paper, and binding are well chosen, and typographical errors are 

 few. 



The main body of the book, exclusive of the very full table 

 of contents, the preface, introduction, three appendices, and two 

 indexes, is divided into four parts, 26 chapters, and 549 pages, 

 including 89 figures, many of which are half-tones. It has 

 already been reviewed appreciatively and at considerable length 

 by a soil expert,* and the present reviewer does not feel quali- 

 fied to add anything to what has been said about the first three 

 parts, which treat of the origin, physics, and chemistry of soils. 

 Part 4, entitled " Soils and Native Vegetation," which contains 

 brief repetitions of some of the essential features of the three 

 preceding parts, together with much additional matter, will in- 

 terest botanists most, though the rest of the book contains many 

 botanical references and is well worth studying. 



The study of the relations between soil and vegetation has 

 always been one of Dr. Hilgard's specialties. He points out here 

 the difficulty of reaching correct conclusions on this subject in 

 Europe, where most of the soils were cultivated and fertilized for 

 generations before botany became a science, and deplores the 

 scarcity of accurate observations in America, where the character 

 of the original vegetation is known by tradition nearly everywhere 

 where it does not still exist. His view, as expressed in the pref- 

 ace and two or three other places in the book, as well as in some 

 earlier publications, is that "the native vegetation represents, 

 within the climatic limits of the regional flora, the result of a secu- 

 lar process of adaptation of plants to climates and soils, by 

 natural selection and the survival of the fittest. The natural 

 floras and sylvas are thus the expression of secular, or rather 

 millennial experience, which if rightly interpreted must convey to 

 the cultivator of the soil the same information that otherwise he 

 must acquire by long and costly personal experience." In this 



*F, H. King in Science II. 24 : 681-684. 30 N 1906. 



