172 tHE PLANT WORLD 



Book Reviews. 



On the Physics and Physiology of Protoplasmic Streaming in 

 Plants. By Alfred J. Eivart, D. L. C. Royal 8vo, 131 pp., 17 

 illustrations. $2.90. The Clarendon Press, Henry Frowde. London, 

 Edinburg, and New York, 1903. 



The present volume not only contains a summary of what has already 

 been learned about protoplasmic streaming, but also the results of many 

 experiments and observations made by the author. The matter is divided 

 into four chapters and an appendix, as follows: I. Introduction; II. 

 Physics and Chemistry ; III. Physiology; IV. Theoretical and General. 

 The appendix discusses the electrical conductivity of egg-albumen. 



As early as 1774 the streaming movement of protoplasm in plants was 

 observed and described by Corti, an Italian botanist. It has been a sub- 

 .ject of much interest to investigators as well as amateurs ever since. 

 Under the head of physics and chemistry phenomena are considered 

 which may be attributed to physical and chemical causes, such as osmotic 

 pressure, viscosity, electrical and magnetic influences, and the chemical 

 changes occurring. Under physiology, what may be called vital phenom- 

 ena, such as can not in the present state of our knowledge be referred to 

 chemical or physical causes, are treated. The work is comprehensive 

 and will be indispenable to all physiological botanists. c. L. S. 



Economic Plants of Porto Rico. By O. F. Cook and G. N. 

 Collins. Illustrated. Smithsonian Institution, Contributions from the 

 United States National Herbarium, Vol. VIII, Part 2. 



This is one of the most valuable works yet issued in the series to 

 which it belongs. It is in the form of an annotated alphabetical list, and 

 might well be called a dictionary of the economic plants of the West 

 Indies. The Spanish names are fully defined and explained, while im- 

 portant products, like the banana and cocoanut, are made the subjects of 

 elaborate essays, dealing with methods of cultivation, the value and dis- 

 tribution of different varieties, etc. The book is rendered more valuable 

 by the fact that the authors have incorporated practically all the informa- 

 tion contained in the works of Bello, Stahl, Hansard and Grosourdy. 



c. L. P. 



