62 



NATURE 



[March 27, 1919 



escaped the editor; but generally the combined 

 efforts of translator and editor have been most 

 successful. As in the other volumes, the newly 

 appended references will prove of considerable 

 value. J. S. Macdonald. 



SOUTH AFRICAN GRASSLANDS. 



The Grasses and Grasslands of South Africa. By 

 Prof. J. W. Bews. ' Pp. vi+ i6i. (Pietermaritz- 

 burg- : P. Davis and Sons, Ltd., 1918.) Price 

 75. 6d. net. 



rHIS little volume is a contribution to the study 

 of South African plant ecology, a subject on 

 which Prof. Bews has already published several 

 papers. In studying- the plant succession in the 

 grasslands of South Africa, it was found necessary 

 to devise a simpler means of identifying the species 

 than that afforded by the key to the genera given 

 by Dr. Stapf in his elaborate account of the 

 grasses in the "Flora Capensis." An artificial 

 key was therefore drawn up, and has been in- 

 cluded in the present volume. The test of such 

 a key is its value to the working field botanist, 

 and Prof. Bews states that it has met with the 

 approval of his fellow-workers. Following the key 

 are a number of ecological notes on the principal 

 species in each genus, the genera being arranged 

 in alphabetical order. These notes embody many 

 of the author's observations, his object being to 

 set forth the principal facts that have been ascer- 

 tained regarding the part played by the more 

 important species in the grassland plant suc- 

 cession, and also by means of selected ex- 

 amples to illustrate the general differences which 

 are shown in morphological characters, and par- 

 ticularly in leaf-anatomy. 



The study of a simple transverse section of the 

 leaf of a grass may give more information as to 

 its nutritive value than an elaborate chemical 

 analysis of the herbage, for the latter will vary 

 greatly according to the time of year, and even 

 according to the state of the weather. Xero- 

 phytic grasses, in which the leaves have to protect 

 themselves against excessive transpiration, grow- 

 less quickly, and are not so valuable for pasturage 

 , as the more mesophytic types. A notable excep- 

 tion to this rule is Danthonia purpurea, Haas 

 grass, or hare grass. Although in general appear- 

 ance this is a xerophytic plant, farmers are agreed 

 that it is also a very nutritious species. It is low- 

 growing, being rarely more than an inch or two 

 in height, with deep roots and numerous densely 

 leafy shoots, and is peculiarly adapted to growing 

 over the surface of hard-baked clay soils. It has 

 become completely dominant in the grass veld 

 for miles around Molteno, in the Stormberg 

 region, near the eastern edge of the Karroo. 



The ecological notes are illustrated by some- 

 what diagrammatic cross-sections of the leaves 

 iof the more important species, which indicate 

 especially the distribution of the hard, mechanical 

 tissue. The author then gives a general sketch 

 of, the grasslands of South Africa and their 

 development. Five main regions are considered 

 NO. 2578, VOL. 103] 



— namely, the south-western or Cape region, the 

 western region, the sand veld region, the Karroo 

 and Karroid central region, and the eastern grass 

 veld region. The boundaries of these regions are 

 shown in a map which forms the frontispiece. 

 Finally, a short section is devoted to some 

 economic questions concerned with grass-burning, 

 stock-grazing, the feeding value of natural 

 grasses, the cultivation of grasses, and soil 

 erosion. An appendix gives in tabular form a list 

 of English, Dutch, Zulu, and Sesuto names. A 

 striking feature is the large number of names in 

 the Zulu indicating a remarkable discrimination 

 of species. 



COLLOQUIAL CHEMISTRY. 

 Everyman's Chemistry. The Chemist's Point of 

 View and his Recent Work told for the Lay- 

 man. By Ellwood Hendrick. Pp. x-Fsig. 

 (London : University of London Press, Ltd. , 

 1918.) Price 85. 6d. net. 



MR. HENDRICK has written an extremely 

 original book. To use his own words : 

 "The whole thing is a sporting proposition 

 between you, the reader, and me. If I can hold 

 your attention until you have read it through, I 

 shall have succeeded in my intention." It is only 

 fair to say that, if the reader possesses ordinary 

 intelligence, he will be able to pick up a good deal 

 of interesting information from the book, even if 

 he comes away from it with confused ideas as tc 

 how chemists attain their results. 



The style is colloquial in the extreme, and no 

 one need be deterred from Beginning the book 

 by any fear of high-and-dry treatment, whilst the 

 professional chemist will derive a good deal of 

 amusement from the manner in which facts are 

 presented. A few of Mr. Hendrick's headings 

 will make clear what is meant : " Polygamy in 

 Chemistry"; "Nitrogen, its Satanic Tricks"; 

 "The Old Horse of Chemistry"; "The Iron- 

 master's Torment and Why he Swears"; "The 

 Chemical Old Mare"; "The Grand Old Tramp 

 who Left his Mark"; "The Red-headed Halo- 

 gens." 



It would be a mistake to suppose, however, 

 that Mr. Hendrick has not done a useful piece of 

 work in writing the book. He has kept in view 

 the fact that the man in the street is not particu- 

 larly interested in theory, but prefers to learn 

 something about practice; and it is safe to say 

 that few popular books contain such a mass of 

 examples of the application of chemistry to prac- 

 tical problems. No one who reads this work can 

 fail to appreciate the manner in which chemistry 

 has permeated the whole of modern society. The 

 uses of sulphuric acid, described on pp. 86-88, 

 should awaken the layman to the fact that, from 

 the time he turns on the tap of his bath in the 

 morning until he finishes his breakfast, he is con- 

 tinually coming in contact with materials the pro- 

 duction of which is possible only owing to the 

 employment of sulphuric acid. And when prose 



