278 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



but the contents may be summarised with the general remark that every 

 subject is treated exhaustively and accompanied by an abundance of 

 references, so that the student is provided with a full equipment for the 

 purpose of studying any and every branch of physiology. 



There are six chapters, the first four dealing with "movement" ; for 

 instance, Chapter I. discusses the forms, causes, and mechanism of move- 

 ment, Chapter II. is on the movements of curvature ; Chapter III. on 

 tropical curvatures ; Chapter IV. on locomotory and protoplasmic move- 

 ments : while Chapters V. and VI. are on the production of heat, light, 

 electricity, and the sources and transformations of energy in the plant. 



It may be almost said that the student will find everything that he 

 may want in this encyclopaedic work on the subjects dealt with. 



" Evolution and Adaptation." By T. H. Morgan, Ph.D. 8vo., 470 pp. 

 (Macmillan, London.) 12s. 6J. net. 



The object of this work is to regard De Vries' Mutation Theory as the 

 basis of evolution, instead of Darwin's Origin of Species by Means of 

 Natural Selection. It contains thirteen chapters, dealing with the 

 problem of adaptation, the theory of evolution, Darwinism, inheritance of 

 acquired characters, the origin of the different kinds of adaptation, &c. 



Mutations, or suddenly appearing species, are supposed to arise from 

 internal impulses, but the author declines to enter into any discussion as 

 to causes of variation. If a mutation should be in adaptation with certain 

 external factors of an environment, it must somehow find its way to them. 

 Hence, as in Darwin's theory, mutations are supposed to arise without 

 any natural law connecting them with suitable conditions of life. Hence 

 he accounts for the degenerate wings of domesticated ducks by thinking 

 " those ducks would have been most likely to remain in confinement that 

 had less well -developed wings." 



He accepts neither Darwin's theory nor the present-day explanation of 

 adaptation as made by ecologists, who find they are impelled to see 

 "adaptation" in their plant-surveying. 



He asserts that " the effects of climate and food are only transitory 

 factors " ; but he omits to add they may become fixed and hereditary by 

 remaining for several generations in the same conditions. 



In conclusion, the author's object appears to be to substitute mutations 

 for Darwin's variations with successive additions, so that complete 

 adaptations are acquired at once and the new species is made ; but he 

 cannot bring the mutation and a fitting environment together. 



" The Horticultural Note Book." By J. C. Newsham. 8vo., 118 pp. 

 (Crosby Lockwood & Son, London.) 75. 6d. net. 



Of all the many books published on gardening subjects none are more 

 worthy of a place in the amateur's or gardener's library than this excellent 

 little work. It is of handy size for the pocket, well bound in a strong 

 pliable cover, and contains very valuable information on most subjects 

 of interest connected with horticulture. It is so comprehensive that only 

 a tithe of the scientific and practical information can be mentioned. 

 Land measurement, horticultural building, garden formation, geological 



