March 27, 19U3.] 



SCIENCE. 



5K 



ecological plant-geography, or phytogeography, 

 the study of the ecology of the vegetation of 

 particular regions. It aims to elucidate the 

 factors determining not only the adaptations 

 of species (vegetation forms) to their habitats, 

 but also their association into groups (forma- 

 tions \_societies^, associations^ etc.) constitu- 

 ting the plant-life of any region, a subject of 

 the greatest educational and popular, as well 

 as scientific, interest. Such investigation is 

 still so new as to exliibit many of the crudities 

 of youth, and its methods and terminology are 

 yet undifferentiated; but the field is attract- 

 ive and promises rich results to a truly scien- 

 tific attack. In this country there are three 

 active centers of phytogeographical study, the 

 universities of Nebraska, Chicago and Min- 

 nesota. Under the auspices of the botanical 

 seminar of the University of Nebraska, Drs. 

 Pound and Clements have published a vol- 

 ume, ' The Phytogeography of Nebraska ' 

 (Second ed., 1900) which represents the most 

 extensive and thorough ecological study, from 

 a scientific standpoint, of the vegetation of a 

 particular region which has been attempted 

 in this country. And now one of the authors, 

 Dr. Clements, has taken the lead in a work of 

 another kind which is likely to be much fol- 

 lowed in the near future, namely, the prepara- 

 tion of sets of herbarium specimens, supple- 

 mented by photographs, to illustrate by these 

 two most accurate of available methods the 

 phytogeography of an important region in the 

 Rocky Mountains, and he has placed a num- 

 ber of these sets at the disposal of other insti- 

 tutions and students. 



This collection consists of herbarium speci- 

 mens of standard size and most excellent pre- 

 servation illustrating some 533 species of 

 prominent Colorado mountain-plants, supple- 

 mented by 101 photographs 6x8 inches, the 

 great majority of which leave nothing to be 

 desired in the clearness of illustration of their 

 subject and in artistic photographic excellence. 

 They are selected to show either individual 

 prominent plants (the vegetation forms), or 

 associations of these (facies) or the larger 

 groups occupying characteristic situations 

 (formations), while a few illustrate special 

 features of reforestation, etc. Equally im- 



portant with specimens and photographs are 

 the labels, of which a specimen taken at ran- 

 dom reads thus : 



HEEBAEIA FOEMATIONUM COLOKADENSIUM 

 F. E. et B. S. CLEMENTS. 



93. Geniiana affinis Griseb. 

 Herba rhizomatica endemioa, Minn-NM- 

 Nev-BC, species principalis aspectus autum- 

 nalis PinuS' ponderosa-flexilis-xero-hylio. 

 Crystal Park 2600 m. 4 Septembris 1901. 



The labels thus give, in addition to the more 

 usual information, a short characterization of 

 the vegetation form and a mention of its place 

 in a particular formation, e. g., the Pinus 

 ■ponderosa and flexilis dry forest. The labels 

 thus embody Dr. Clements's new proposals for 

 phytogeographical nomenclature, an extremely 

 carefully and judiciously elaborated system 

 which the author has since published in Bug- 

 ler's 'Botanische Jahrbiicher' (Beiblatt No. 

 70, 1902). His system consists essentially of 

 the naming of formations by combining the 

 genus (and species) names of the prominent 

 vegetation forms with terms from Latin and 

 Greek roots precisely descriptive of the habi- 

 tats. It is of course yet too early to permit 

 of any prediction as to how widely the system 

 will be followed, but there can be no doubt 

 that it is much the most serious attack upon 

 this important problem that has yet been made, 

 and not only must future workers take ae- 

 oount of it, but it is very likely to form the 

 foundation of the permanent system. In this 

 admirable collection Dr. Clements thus char- 

 acterizes some sixteen formations, and shows 

 the place in each of the various vegetation 

 forms, while a set of check-labels makes the 

 classification easy and plain. When one ex- 

 amines these specimens in close comparison 

 with the photographs, bringing the two 

 into correlation by use of the labels, he has 

 the means of obtaining the most accurate and 

 vivid impression of the vegetation of this 

 region that can possibly be obtained without 

 an actual visit. For this reason it is alto- 

 gether likely that the method will be exten- 

 sively used in the future in the description 

 and illustration of the phytogeography of the 

 different regions of the earth, both as a means 



