REVIEWS. 173 



afiforded by the flower itself, but also in the light of the literature 

 on the subjecct, c. g.. Ogle, Farrer, ^Nliiller and Darwin. 



The sentence, " We may dismiss at once, as obviously in con- 

 flict with notorious and indisputable facts, the hypothesis that 

 mutations are stable, and therefore are the materials of evolution, 

 because their transmission is ^^lendelian " (p. 363). is not entirely 

 clear, but there is. no doubt of the author's meaning in the follow- 

 ing paragraph. 



" The mutation theory of evolution is quite impossible. If, 

 instead of groping in the comparative obscurit\- which surrounds 

 wild nature . . . men had turned their attention to the clear, 

 voluminous, decisive evidence, much of it statistical, afiforded by 

 their own species, it would never have been propounded." 



It is doubtless quite true that, if no one had ever studied varia- 

 tion in a mutating species, mutation, and its bearing on evolution, 

 would never have been discovered. 



Liclicnology for Bci:;iniicrs. By Frederick Lekoy Sargent. 

 Pamphlet, illustrated. Pp. 20. The Harvard Cooperative So- 

 ciety, Cambridge, Mass. Fifty cents. 



This helpful little pamphlet is a reprint from the Bryoloi^ist, 

 A^ol. 8, 1905. The first fifteen pages tell the beginner the nature 

 of the lichen, when, how, and where to collect, and how to pre- 

 serve and study the specimens, and prepare them for the her- 

 barium. A schedule for analysis is given, and also a brief bib- 

 liography. The last five pages are occupied with an artificial key 

 to species. This booklet brings the elements of lichenology within 

 easv reach of the beginning student. 



C. S. G. 



Xczc Creations in Plant Life. By W. L. Harwood. i2mo. Pp. 

 xiv -\- 368, 49 full-page plates. $1.75 net. The ]\Iacmillan 

 Company. 



The public has awaited with interest the appearance of this 

 long-heralded book, the first supposedly authentic account of the 

 lifework of Luther Burbank. That it has proven a distinct dis- 

 appointment seems to be due primarily to Mr. Burbank's unfor- 



