Vegetable Physiology. 



— Ekwin F. Smith. 

 Desert Vegetation. — Perhaps the most interesting part of Rev. 

 George Henslow's recent book, The Origin of Plant Structures, are the 

 two chapters on desert plants. The first of these chapters is devoted 

 to a consideration of the origin of the morphological peculiarities of 

 desert plants ; the second to the histological peculiarities of such plants. 

 A large amount of data are brought together, rather hastily it would 

 appear, going to show that the peculiarities of desert plants are the 

 direct outcome of the conditions under which they grow, in other words, 

 that these peculiar modifications, such as reduction of leaf surface, in- 

 crease of succulency, acquisition of spines, development of water storage 

 tissues, sinking of the stomata below the level of the surface, excessive 

 development of cuticle, of wax, or of hairiness, change from annual to 

 biennial or perennial, increased length of roots, etc., are all brought 

 about by the direct action of environment on the plant. "Natural 

 selection," in the author's own words, " plays no part in the origin of 

 species." These two chapters are well worth the perusal of all who are 

 interested in the study of the flora of our western mountains and arid 

 plains, and the whole book will serve to provoke thought. Other 

 chapters deal with origin of structural peculiarities of alpine and arctic 

 plants; maritime and saline plants; phanerogamous aquatic plants, 

 etc. The book is a companion volume to the author's Origin of Floral 



A Second Rafinesque. — Die Pestkrankheih-u Unpvti<,n.d-,'<uik- 

 heiten) der KnU urgewachse ; Nach streng bakteriologischer Met h ode 

 uutersueht nod in rdllign l^brrriiistimmtiiig mit Robert Koeh* Entdeck- 

 ungen gcschildert vo» Prof. Br. Ermt Hallier, is one of the querest 

 books it was ever the lot of the writer to read. It was published at 

 Stuttgart in 1895 by Erwin Niigale, and contains 144 8 vo. pages and 

 7 fairly well executed plates. Concerning this book it may be said 

 that its author is either an undiscovered great genius or else a very 

 crazy man. About one-third of the book is given up to caustic abuse 

 of Anton de Bary and his students, relative to which it may be said 

 that Dr. de Bary's reputation is safe not only in the hands of his 

 friends but also in the hands of all who love clear thinking and honest 

 work ; and all this without defending any of the errors into which he 

 may have fallen. Another third of the book or thereabouts is devoted 

 to the description of old and well known species of Peronosporaceie, 



