April 4, 1913] 



SCIENCE 



529 



sized. We like the opening sentences in 

 Chapter III., and can not refrain from quot- 

 ing some of them, as follows : 



Every citizen in every country is interested, or 

 should be interested, in good scenery. Of the 

 various elements that constitute good scenery or 

 that go to make up our landscape there are none so 

 ornamental nor so indispensable as trees. 



In discussions relating to the conservation of 

 our natural resources, therefore, the element of 

 good scenery should always be considered. Since 

 good forests, good farms and good waterways con- 

 tribute largely to the landscape, the element of 

 good scenery can not easily be separated from 

 many of the commonly recognized natural re- 

 sources. 



Trees have become so much a part of our 

 civilization that it would seem almost impossible to 

 get along without them. What would our homes, 

 OUT country roads, our city streets, our parks, and 

 our landscape be without them? We all know that 

 trees are beautiful and even necessary in such 

 places, but we can not fully appreciate their value 

 till we have seen the desert. 



The value of trees from the economic or com- 

 mercial standpoint is well understood and can be 

 estimated on the basis of dollars and cents. Their 

 esthetic value and their value from the standpoint 

 of health is not so generally appreciated nor is it 

 so amenable to calculation. We hear a great deal 

 these days about surveys — forest surveys, agricul- 

 tural surveys and the like. A survey in this sense 

 means an inventory or a stock-taking. It would be 

 interesting to make a survey based upon the land- 

 scape wealth of any section or of the whole coun- 

 try. It would be interesting also to compare in 

 such a survey the relative value of the various ele- 

 ments of the landscape. It seems safe to predict 

 that in most sections trees would be credited with 

 a very large proportion of the total wealth. 



And again in Chapter IV., we find these 

 suggestive sentences: 



When we think of the open country we are re- 

 minded of the cool and shady roads, although some 

 country roads are not so alluring as they ought to 

 be. The thought is comforting. On the other 

 hand, when we think of conditions in the city, the 

 hot and dazzling pavements present themselves 

 vividly to our memory. The thought is anything 

 but comforting. Blessed is the city that is well 

 supplied with trees. 



The attractiveness of a city depends largely upon 



its trees. A city without trees can not be attrac- 

 tive, and the more trees withia the city limits, the 

 more attractive is the city likely to be. 



Passing to the systematic part of the book 

 there is first a general chapter on the identifi- 

 cation of trees, with such explanation of 

 terms as will render this work easier for the 

 • beginner. Then follow various keys, as (1) a 

 key to genera, (2) keys to the conifers, (3) 

 keys to the various kinds of deciduous trees. 

 These keys refer to full-page descriptions and 

 discussions of the particular species, and on 

 the opposite page is a full-page plate of char- 

 acteristic illustrations made by " half-tone " 

 process from carefully selected photographs. 

 These descriptions cover habit, bark, twigs, 

 leaves (in evergreens only), buds, fruit, com- 

 parisons with other species, distribution, and 

 wood characters. Preceding the descriptive 

 matter is an English name, followed by the 

 scientific name, very properly in a book like 

 this, accompanied by the " authority " for the 

 species. A convenient glossary and a well ar- 

 ranged index complete this useful book. The 

 binders have enclosed the text in a pretty and 

 appropriate cover in keeping with its title. 

 Charles E. Bessey 



The University op Nebraska 



Science and the Human Mind, a Critical and 

 Historical Account of the Development of 

 Natural Knowledge. By William Cecil 

 Dampier Whetham, M.A., F.E.S., Fellow 

 and Tutor of Trinity College, Cambridge, 

 and Catherine Burning Whetham, his 

 wife. New York, Longmans, Green, and 

 Co. 1912. Pp. xii + 304. Price, $1.60 net. 

 This work consists of an Introduction, and 

 of six chapters on Science in the Aucient 

 World, the Medieval Mind, the Renaissance 

 and its Achievement, the Physics of the Nine- 

 teenth Century, the Coming of Evolution, and 

 the Last Stage; of a good bibliography (pp. 

 287-296), and of a full index. The authors 

 are already known favorably to scientific men 

 by their " A Treatise on the Theory of Solu- 

 tion " and " The Theory of Experimental 

 Electricity " ; to the general public by their 

 admirable " The Recent Advance of Physical 



