488 SCIENCE PROGRESS 



financial returns, though the forests of the Landes yield about 6 per cent. 

 on the invested capital. The conversion of a fever-stricken and thinly- 

 populated waste into a healthy and prosperous region that has become a 

 national asset is a feat of which any Government department has a right 

 to be proud. 



It is achievements such as these which command our respect for the 

 French forest service, and in making the story of its work more widely acces- 

 sible the author has earned the gratitude of all students of forestry and its 

 methods. It is, however, rather as the considered opinion of an experienced 

 American forester on French forests and forestry that the chief interest of 

 these pages lies. 



The last chapter gives an account of the work of the American forest 

 engineers in France, and brings home to one not only the importance of timber 

 in modern warfare, but also the enormous demands which could not have 

 been met but for the efficiency with which the French forests had been 

 managed. Some idea of the magnitude of the drain which the war entailed 

 can be gathered from the fact that the Americans alone cut two million 

 board feet per diem ! Not without some reason does the author say that the 

 American lumbermen, used as they were to the huge trees and extensive 

 forests of the West, " took off their hats " to the service which raised the timber 

 that it fell to their lot to cut. E. J. S. 



Breeding Crop Plants. By Prof. H. K. Hayes and Prof. R. J. Garber. 



[Pp. xviii + 328, with frontispiece and 66 other illustrations.] (New 

 York: McGraw-Hill Book Co., 1921. Price 21s. net.) 



A BOOK conceived on practical lines, and containing a great deal of information 

 useful both to the breeder and grower. 



Most of the more important work on the genetics of crop plants is sum- 

 marised, with references to a Bibliography occupying some twenty pages and 

 containing citations to about five hundred original papers. 



Despite the comparative infancy of the commercial application of genetical 

 methods, one is impressed, in reading these pages, by the number and importance 

 of its achievements. Rust-resistant strains of cereals with improved yield, 

 " Mosaic " resistant beans, high-yielding cottons and tobaccos, are merely 

 a few of the better-known examples of what have been already produced. It 

 is not only as showing what has been done that the chapters devoted to 

 particular species are useful, but also as indicating what there is still to do. 



In most of the species treated the probable origin of the cultivated form 

 is considered, with some account of the related wild types. The chief strains 

 grown are summarised, as well as their ascertained behaviour under control. 



In the historical resume which serves as an introduction it is of interest 

 to learn that an Englishman, one John Goss, had, in 1820, observed segrega- 

 tion in controlled crosses, although he did not formulate therefrom any 

 generalisation such as we owe to Mendel. Only six years later Sargeret in 

 France recognised dominance in melons. 



A considerable amount of space is devoted to experimental methods in 

 which both the theoretical and practical aspects receive due recognition. 



E. J. S. 



Lichens. By Annie Lorrain Smith, F.L.S. Acting-Assistant, Botanical 

 Department, British Museum. [Pp. xxviii -1- 464, with 135 figures 

 in the text.] (Cambridge: at the University Press, 1921. Price 

 55s. net.) 



This is the second volume issued of the projected Cambridge Botanical 

 Handbooks, the first being Volume I. of the Algae. Its publication was delayed 



