1894. SOME NEW BOOKS. 307 



animals. The common Hydra, as usual, merits a full share of atten- 

 tion, and we are pleased to observe some reference to the correction 

 of the commonly-accepted errors resulting from Trembley's experi- 

 ments on this animal. The worms follow, and are described in the 

 words of Huxley as a " heterogeneous mob." Rotifers, of course, 

 are treated at considerable length, and there are good figures — some 

 original, some after Hudson. The Polyzoa are also very well 

 described. Chapter V. relates to the larvae and more minute forms 

 of starfishes, arthropods, and molluscs ; but this would bear much 

 expansion and further illustration with advantage. 



The concluding chapter on the micro-aquarium will be found as 

 useful as that on collecting, and interest is added to it by a repro- 

 duction of the original engraving of Trembley's study, showing the 

 glass jars in which the well-known experiments on Hydra were made. 

 A view of the author's arrangements forms the frontispiece. A good 

 index is appended. 



A History of the World. 



HisTOiRE DU Monde: son Evolution et sa Civilisation. By Etienne Guyard. 

 8vo. Pp. 700, with Schrader's Planisphere. Paris : published by Author, 5, 

 Impasse Nicole, 1894. Price 7 fr. 



This is a somewhat strange work by a former professor in the 

 Imperial Military Academy of Japan. It is the first volume of a 

 projected series of five, intended to be a popular account of the 

 astronomical and geological history of the globe itself, an outline of 

 the evolution of its animals and plants, and a general synopsis of the 

 history of man from primaeval times to the conditions of modern 

 political and social life. The volume before us treats of astronomy, 

 botany, zoology, geology, anthropology, and the history of the 

 progress of organic evolution, and bears evidence of having been 

 most laboriously compiled from the best modern sources. So far 

 as we have been able to test them, the statements are generally 

 clear and reliable; while to those who desire only a superficial 

 knowledge of the multifarious subjects treated, and do not object to 

 a somewhat bald, encyclopaedic style, the work will doubtless prove 

 itself very useful. The great inconvenience in the book, in our 

 opinion, is, that the author has adopted the Oriental custom of 

 placing the title page at what we term the end, while the pagination 

 is exactly the reverse of the ordinary. Moreover, there is a great 

 dearth of illustrations. The appended maps, however, are very good, 

 and the bulk of the volume would doubtless be too much increased 

 if every section were illustrated in the manner customary in special 

 treatises. 



Plant Physiology. 



Experimental Plant Physiology. By Dr. Walter Oels. Translated and edited 

 by D. T. Macdougal, University of Minnesota. Svo. Pp. 86, with 77 illustra- 

 tions. Minnesota : Morris & Wilson, 1894. 



This English edition of Dr. Oel's admirable little book will prove 

 a useful guide to a series of elementary experiments in illustra- 

 tion of the most important principles of plant-life. The many clear 

 and excellent illustrations form a valuable supplement to the descrip- 

 tions. The contents are arranged under the following headings: 

 derivation of nutriment from soil and water ; transpiration ; photo- 

 synthesis (a term suggested by Professor Conway Macmillan to express 



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