BOOK EEVIEWS. 



189 



A considerable number of experiments with plants are well and 

 clearly illustrated and described, as a rule, sufficiently to enable anyone 

 to perform them. It might have been mentioned, however, with regard 

 to the experiment (fig. 3) on p. 22, that a water plant should be used, 

 and it would probably be better to omit the well-known demonstration of 

 the effect of light in assimilation by means of a stencil (p. 27 and fig. 5.) 

 The material used for preventing the incidence of light prevents also the 

 access of air, and a transparent] glass stencil will produce precisely 

 similar results. Some of the stomata in the diagram on fig. 10 (p. 38) 

 appear rather unnatural. These little points, however, and a few others 

 like them, where the author has merely followed one or two popular 

 approximations to truth, detract nothing from the general excellence of 

 the book, which lucidly and interestingly details the main facts in the 

 nutrition of plants and animals, and we can heartily commend it to 

 the practical man and to^ the student, who will find here a sound basis 

 for future work. 



The book is singularly free from misprints (though, perhaps, 

 " troubled " on p. 24, should be " turbid "), and the illustrations are 

 excellent. 



"The Natural History of Coal." By E. A. Newell Arber, M.A., 



F. L.S. 8vo., X. + 163 pp. (University Press, Cambridge, 1911.) 

 Is. net. 



The author deals in a most interesting fashion with the nature, 

 origin, and mode of formation of the various types of coal, lignite, &c. 



"The Liverworts, British and Foreign." By Sir Edward Fry, 



G. C.B., and Agnes Fry. Svo., viii. + 74 pp. (Witherby, London, 

 1911.) 2s. 6d, net. 



Those familiar with the httle book by the same authors on 

 * * Mosses ' ' will expect to find in this an interesting and reliable account 

 of their near relatives, and they will not be disappointed. Anyone who 

 takes an interest in the lower types of vegetation in the wood or garden 

 beyond regarding them as a nuisance when they occur on his pots of 

 seedlings, will find an excellent account of the history and structure of 

 these moss-allies in this little book. 



" The Modern Culture of Sweet Peas." By Thomas Stevenson. 

 8vo. 86 pp. (The Cable Printing Co., London, 1910.) 3s. net. 



Of the making of sweet pea books there seems no end. This one 

 of Mr. Stevenson's, however, is one of the most practical that has come 

 into our hands. He treats in a thorough fashion the questions of soil 

 and situation, time of sowing and planting out, staking, mulching, feed- 

 ing and watering; varieties for exhibition, for garden decoration, for 

 market and for indoor decoration. There are also chapters on early 

 flowering in pots, and the decorative value of sweet peas. Six very 

 well-executed coloured plates are given, besides several half-tone blocks. 

 The latter are most valuable, as they convey an excellent idea of Mr. 



