54 TRANSACTIONS OF THE [ Sess. nxxrv. 
Edinburgh, for the first of the more recent papers by the 
late Robert Smith dealt with the Pentlands? That memoir 
contains a sketch of the author's objects in undertaking 
botanical surveys and outlines his methods; although in 
many ways it was a new method of attacking problems of 
botanical distribution, it has many links with the work of 
the older British botanists. 
In order to define “what is botanical survey,” it is 
necessary to appreciate the various lines of study involved 
in plant-geography, a branch of botany which im recent 
decades has made rapid progress. Plant-geography seeks 
to answer three questions: what plants occur in the world ; 
where they occur; why they occur in one part and not in 
another. The data required to answer the first two 
questions results in the preparation of a “flora,” and in 
the botanical exploration of a country this is the first step 
towards knowledge of the plants. It entails the observation 
of all the plants in the area, and the recording of their 
distribution. Most of the phytogeographical work in 
Britain, as in other countries, has been of this kind, and it 
has resulted in a series of fioras of the country as a whole, 
and of counties and other subdivisions. From studies of 
this kind has arisen the branch of fioristic plant-geography 
which, as recently defined by A. Engler? has for its aims: 
(a) to prepare a floral catalogue arranged im species, genera, 
etc.: (b) to prepare statistics as to abundance and frequency ; 
(c) to study the physiognomy, i.e. to distinguish the pre- 
vailing groups of the flora—forest, bush, heath, ete.—and 
to ascertain their distribution; (d) to divide up the area 
into floral regions; (¢) to study the history of the flora. 
The monographs in the series “ Vegetation der Erde,” 
edited by Engler and Drude, are outstanding examples of 
floristic plant-geography. In Scotland, Professor Trail’s 
“ Topographical Botany ”* is an important contribution to 
floristic studies. 
The attempt to answer the question why plants occur in 
one place and not in another, involves consideration of 
* Smith, Robert, “Botanical Survey of Scotland; L Edinburgh 
District,” Scot. Geog. Mag., July 1900. 
* Engler, A., “ Humboldt-Centenar-Schrift d. Gesell. f. Erdkunde zu 
Berlin,” 1899. 
* Trail, J. W. HL, “ Annals of Scottish Natural History.” 
