BOOK REVIEW'S. 



353 



goniates I. ; The Archegoniates II. ; Flowering Plants; Fossil Plants; 

 The Food of Plants ; Perpetuation of the Race ; Defences ; Ecology, 

 and Index. 



In every case good types are selected and described in a clear and 

 instructive manner, admirably suited for a beginner in the study of 

 botany. 



Though the word " evolution " occurs in the second chapter (and 

 not in the Index), it only refers to microscopic algae. 



With regard to cross- and self-fertilization, the author rightly 

 emphasizes the mistake Darwin made in concluding from his experi- 

 ments that the latter was injurious ; but he misses the point of 

 there being any special advantage in cross-pollination. It is now 

 known that self-fertilizing plants are far more widely spread over 

 the world and set far more seed than larger-flowered cross-pollinated 

 plants. So that we must look for the true cause of the inferiority of 

 cross-pollinated flowers. If the theory be true that insects are the 

 " cause " of larger flowers as well as of " irregularity," then this 

 enhancement of the non-essential whorls is done at the expense of the 

 essential ones. Health and plenty of seeds are the two " ends " of 

 plant-life ; " improvements," in the gardener's eye, are of no account 

 to plants. A small plant of the habitually self-fertilizing bittercress 

 can bear 4,000 seeds and more. 



Though he does not refer to the process of evolution under that 

 word, he is right in echoing Warming's and Schimper's words in saying, 

 " Given external conditions to act as stimuli, we may be assured that 

 living protoplasm is fully capable of response, and that in Life itself 

 there are potentialities which will lead to wonderful results " ; such 

 being the evolution of all plants, past, present, and future. 



The author rightly applies this to the origin of spines and other 

 so-called " defences " of plants, as the result of drought, and not for 

 any useful purpose. If the spines of the rest-harrow to which he 

 refers keep off rodents, so much the better, but its spineless ally is no 

 more eaten than any other herb. 



So, too, poison is no protection if caterpillars, which can feed on 

 poisonous plants, attack them. Animals do not " instinctively " 

 avoid all such, for cattle have often died from eating yew leaves. 



Taking the book in its entirety, it is an admirably compiled 

 exposition of the leading facts of structure, of a great and well-selected 

 variety of plants. The text and the abundance of figures ought to 

 make the book widely acceptable, though the price is of course heavy. 



" The Study of Plants : An Introduction to Botany and Plant 

 Ecology." By T. W. Woodhead, M.Sc, Ph.D., F.L.S. 8vo. 440 pp. 

 (Clarendon Press, Oxford, 1915.) 5s. 6d. 



This volume contains 440 pages and consists of five parts : 

 i. Vegetative Organs ; ii. Reproductive Organs ; iii. Systematic 

 Botany ; iv. Common Trees and Shrubs ; v. Ecology, to which ten 

 chapters are devoted. 



