7 6 



THE AMERICAN NATURALIST. [Vol. XXXVII. 



did not realize the complexity of the genera with which they were 

 dealing ; but the majority relate to the botanico-horticultural species 

 and varieties published by authors who are still living. The great 

 indefiniteness which surrounds plants of this sort may well raise the 

 question, whether a botanist who undertakes either voluntarily or at 

 the solicitation of some nurseryman to give a scientific name and 

 botanical description to some cultivated plant of which he knows 

 neither the country, habitat, natural origin, nor degree of permanence, 

 is doing more to advance or to block the progress of botanical classi- 

 fication. Happily this sort of work is relatively rare in America. 

 In Europe, however, some botanists of rather high standing seem 

 ever ready to undertake this, the lowest type of taxonomic activity, 

 especially in the already much abused groups of succulents. Cer- 

 tainly Yucca has had its share of such botanico-horticultural treat- 

 ment, and it is therefore a pleasure to see the genus subjected to a 

 critical and scientific revision based so largely upon study of the 

 plants in their natural state. 



It is to be regretted that space was not found in Professor Tre- 

 lease's monograph for a more complete citation of herbarium speci- 

 mens, especially those of standard sets, for no feature of monographic 

 work gives more definiteness and permanent influence to a revision, 

 since by fixing uniform standards in reference collections throughout 

 the world it is of the greatest service in bringing about harmony in 



The paper closes with a resume of the economic uses, phylogeny, 

 and ecology of the Yucceae. A series of outline maps is also intro- 

 duced to show the distribution of the forms known to occur in 

 natUr6 ' B. L. R. 



The International Catalogue. 1 — The first part of the long- 

 expected Royal Society's catalogue of current botanical literature, 

 though dated in May and with the MSS. completed in January 

 last, did not reach the libraries of this country until the middle of 

 August. Aside from general prefatory matter, this first part contains 

 the well-known classification of botany adopted by the Council, and 

 an alphabetical index to the same, in English, French, German, and 

 Italian, followed by a topographical classification in the same lan- 

 guages. The catalogue proper consists of an authors' catalogue, 



i The International Cai 

 M. Botany. Published for 



