A^A TURE 



405 



THURSDAY, DECEMBER 12, 1912. 



VEGETATION STUDIES IN THE NEW 

 WORLD. 

 Die Vegetation der Erde. Sammlung pflanzen- 

 geographischer Monographien. Edited by 

 Prof. A. Engler und Prof. O. Drude. XII., 

 Die Pflanzenwelt der peruanischen Anden in ihren 

 Grundzugen dargestellt. By Prof. A. W'elser- 

 bauer. Pp. xii + 355. Price 20 marks. XIII., 

 Phytogeographic Survey of North America. 

 .A Consideration of the Phytogeography of the 

 North American Continent, including Mexico, 

 Central America, and the West Indies, together 

 with the Evolution of North American Plant 

 Distribution. By Prof. J. W. Harshberger. 

 Pp. Ixiii + 790. Price 40 marks. (Leipzig: 

 W. Engelmann, 191 1.) 



THE two last volumes to be added to 

 Drs. Engler and Drude's series of plant 

 geographical monographs deal with the vegetation 

 of the Peruvian Andes on the one hand, and that 

 of North and Central America and the West Indies 

 on the other. The field in both cases is vast, and 

 Prof. Harshberger's volume is of considerable 

 bulk. Dr. Weberbauer's volume can scarcely be 

 considered a worthy successor to the able mono- 

 graph prepared by Dr. Reiche on plant distribu- 

 tion in Chile (vol. viii. of this series, published in 

 1907), which is all the more a matter of regret 

 since the Peruvian .'Xndine flora is one of particular 

 interest. A good account of the vegetation of 

 this region, in its relation to that of Chile and 

 Argentina in the south and Ecuador to the north, 

 still requires to be written. 



Both volumes are excellently printed and illus- 

 trated, and b)' the illustrations alone Dr. Weber- 

 bauer's book fulfils a certain purpose. 



-A work on the flora of the Peruvian Andes 

 labours under the initial disadvantage of dealing 

 with only a portion of a vast tract of connected 

 country stretching from Chimborazo to the Straits 

 of Magellan. Moreover, since Peru lies so much 

 nearer the equator, the vegetation is much less 

 homogeneous in character than is the case in 

 Chile. Four distinct botanical regions are in- 

 cluded in Peru, each of which demands separate 

 treatment, and the affinities of which lie rather in 

 the longitudinal direction — that is to say, with 

 similarly situated regions of countries to the 

 north and south — than in the transverse. These 

 regions are the coast flora ; the middle region, 

 often desert in character; the alpine-.\ndine flora 

 of the western and central Cordillera, and 



NO. 2250, VOL. go] 



the flora of the moist eastern slopes of the 

 Andes. 



The alpine region may be considered to extend 

 from about 10,000 feet to the limits of vegetation 

 on the western Cordillera, and to include the 

 western slopes of the eastern range. Its flora is 

 in direct continuation with that of northern Argen- 

 tina and Chile, and is remarkably distinct and 

 characteristic, showing very little relationship to 

 that of the lower western slopes, and still less to 

 that which is found as soon as the crest of the 

 eastern Cordillera is crossed. 



This highly-specialised nature of the high 

 .-Vndine flora was fully appreciated by Weddell, 

 and it would have been tar more valuable had 

 the "Chloris Andina " been continued first, and 

 a generalisation on the .A.ndine flora as a whole 

 followed in due course. Much still requires to be 

 done in the careful study of the extensive col- 

 lections of South American plants in European 

 herbaria, and then another Hooker will be needed 

 to give us a masterly review of the vegetation of 

 the Andes as a whole. 



The volume under discussion follows the 

 general plan of the series. The physical geo- 

 graphy of the region is first dealt with; then 

 follows a short second part in which the charac- 

 teristics of the different natural orders found in 

 Peru are mentioned, as well as conspicuous 

 genera, &:c. In Part iii. the general character 

 and distribution of the vegetation is described, 

 and its zones are indicated and discussed in 

 detail. 



The inclusion of the flora of the tropical eastern 

 slopes, which is so Brazilian in its aifinities and 

 so different from the rest of the vegetation, seems 

 almost out of place in a work on the Peruvian 

 .\ndes and cannot be rightly understood without 

 careful comparison with the flora of western 

 Brazil. Dr. Weberbauer's book, taken as a 

 whole, suffers from being more of the nature of 

 an account of his own travels rather than a general 

 treatise. He has travelled far and wide in the 

 Cordillera, and has proved himself to be an ad- 

 mirable collector; but, valuable as is his work in 

 many respects, it does not appear, from the 

 volume under review, that he has thereby 

 constituted himself the proper person to 

 write a comprehensive work on the flora of 

 Peru. 



The task undertaken by Prof. Harshberger is 

 even more vast than that of Dr. Weberbauer, and 

 the result is the accumulation of an immense 

 amount of material which has often been but poorly 

 digested. German readers are to be congratu- 

 lated on being presented with an extract by Prof. 



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