NOTICES OF BOOKS. iri 



the more intricate does it appear to be. The constituents of any one 

 flora, be it ever so characteristic, are hardly ever uniform in their 

 fashion of adaptation. Different plants have different ways of over- 

 coming apparently similar difficulties. What then are the factors which 

 determine the preponderance of this and of that type of structure ? 



To indicate the nature of the circumstances which are thus opera- 

 tive, as clearly as is at present possible, forms the main purpose of 

 Professor Warming's book. He treats first of the physical environment, 

 the soil, climate, illumination, state of the atmosphere, and so on, in its 

 general relation to vegetation, and then proceeds to discuss the individ- 

 ual characteristics exhibited by the various kinds of floras, such as marsh, 

 marine, alpine, xerophilous, epiphytic, and the like. He points out and 

 emphasises the difficulties of finding a ready explanation which shall 

 embrace the constituent features of any one flora, and further indicates 

 how the various types may actually become mingled. 



His book is full of delightful details concerning the relation of 

 different plants with their surroundings, and if the wealth of examples he 

 quotes only serves to frighten some of his readers into a closer acquaint- 

 ance with a few additional forms of life as they live and have their being, 

 he will not have written altogether in vain. But Dr. Warming does far 

 more than this, and we have no hesitation in saying that his book forms 

 one of the most important and stimulating contributions to the botanical 

 literature of recent years. He not only indicates the rational principles 

 which must form the basis of any intelligent study of plant distribution, 

 but his book abounds in hints as to points which are still in need of 

 further elucidation. 



A word of caution is given against the habit of generalising too 

 hastily as to the purpose of this or of that structure. The entire form and 

 habitus of a plant is the result of a compromise between its different 

 parts, and it is only by a careful comparative analysis of form and 

 structure, coupled with a due recognition of the complicated nature of 

 the factors which together make up the environment, that any real 

 advance is to be hoped for. 



Dictionnaire de Physiologic. Par Charles Richet, avec le Collaboration 

 de MM. P. Langlois et L. Lapicque. Tome Premier A — B, ler 

 and 2e Fascicules, pp. 672, 1895. Paris: Ancienne Librairie, 

 Germer Bailliere & Cie. ; Felix Alcan, Editeur. 



The advance of a science may be estimated by the growth of its 

 literature — the method of its growth by the manner in which that litera- 

 ture is arranged. 



In the case of every branch of knowledge it is desirable to possess, 

 in addition to the text-books, hand-books and monographs which are 

 essential to a proper understanding of the subject — some storehouse 

 in which may be found a summarised account of all that is known upon 

 any particular point. It is, moreover, desirable that in such a store- 



A* 



