8o THE PLANT WORLD. 



whereby the roots absorb the water and solutions . and the stems and 

 leaves absorb the carbon dioxide necessary for growth. Aside from 

 bringing in food solutions a certain amount of water is necessary from 

 a purely mechanical point of view, in maintaining the proper disten- 

 tion of the cells, and anything, as for example a thickened epidermis, 

 which tends to prevent the escape of water also prevents the absorp- 

 tion of carbon dioxide. A plant therefore might have a sufficient sup- 

 ply of water, but would starve for the necessary carbon dioxide. This 

 difficulty was surmounted by the formation of stomata. When the 

 stomata are open the carbon dioxide enters and is absorbed by the 

 chlorophyll-bearing cells, and at the same time there is necessarily a 

 considerable loss of water, but as soon as the cells cease to be properly 

 distended the stomata close. From these phenomena Dr. Bessey con- 

 cludes: (i). "That one of the functions of stomata is the admission 

 of carbon dioxide to the chlorophyll-bearing tissues of the plant. (2). 

 That the loss of water by terrestrial plants was originally hurtful, and 

 is so now in many cases. (3). That if plants have utilized this con- 

 stant phenomenon it is for the supply of food matters of secondary 

 importance, as the salts in solution of the water of the soil." — F. H. K. 



■ ■ ■ BOO K REVIEW S . . . 



A Descriptive Catalogue of the Useful Fibre Plants of the World, 

 Including the Structural and Economic Classifcations of 

 Fibres. By Charles Richards Dodge. Report No. 9 U. S. De- 

 partment of Agriculture, Fibre Investigation. Washington: Gov- 

 ernment Printing Office, 1897; pp 361. 



This is without doubt the most extensive and complete account of 

 the useful fibre plants of the world that has ever been published. Its 

 compilation has extended over a period of more than twenty-five 

 years, and its author has spared no pains to make it as full as possible. 

 It includes 1,018 species of useful fi.bres. These are arranged alpha- 

 betically, both under the common and botanical names of the fibre 

 plants described, with numerous cross references, so that it is easy to 

 refer to the desired species. Under the more important species the 

 information given is very complete, including a description of the 

 plant, its habitat and distribution, and the manner of producing 

 the fibre as well as its varied uses. The book is illustrated by twelve 

 full-page plates and over one hundred text figures of important or in- 

 teresting species, and there are three short appendices describing fibre 

 machinery, the identification of fibre, and there are a description and 

 history of lace. The work should do much to stimulate practical re- 

 search. It is unfortunate that the entire edition is exhausted. — F.H.K. 



