*9 
Fundamental Units of Vegetation. 
writings. Duchartre himself does not appear to have used the term 
formation, although his divisions ot the vegetation prove that he held 
the concept quite sharply. Grisebach in his review applies the 
term to Duchartre’s divisions, thus speaking of the formation of the 
dunes, of the salt-water marshes, of siliceous soils, of calcareous soils, 
of argillaceous soils, etc. Such a use of the term was frequently 
adopted by Grisebach (cf. 1846: 73 ; etc.) about this time ; and one 
sees that here Grisebach regarded the formation and the habitat as 
indissolubly connected. However, in his classical work Die Vege¬ 
tation der Erde (1872), the term is used to denote physiognomical 
units, such as tundra, and the forests of definite geographical regions, 
which most later authors agree in subdividing into smaller units. 
Hence, practically every author, however he may use the term, 
may find some support for his procedure in one or other of the writings 
of Grisebach. The greatness of Grisebach must not lead us to 
regard his masterly concept as a fetish ; and the analysis of his 
“ phytogeographical formations” into more definite vegetation units 
is a necessity demanded by the more rigorous methods of modern 
phytogeography. 
Perhaps the most usual application of the term formation by 
present-day investigators is closely akin to the one which Grisebach 
held to in 1846 and 1849; and from this point of view a plant 
formation may be regarded as the vegetation co-existent with a 
definite habitat. 
Several of the “ associations ” of Lecoq (1854, i: 291, ct seq.) are 
either groups of associations or formations. 
Kurz (1870), in a report on the vegetation of the Andaman 
Islands, classified the vegetation into divisions which, to some extent, 
correspond to formations, and subdivided these, in some cases, into 
associations, although Kurz does not use these or any other 
special terms. He described the vegetation (1) of the shores, 
(2) of the coasts, (3) of the high forests of the interior parts, (4) of 
the woodless spots, (5) of the cleared lands, and (6) of the sea. 
Some of these he subdivided into smaller units. Thus, the vege¬ 
tation of the coasts is subdivided into (a) evergreen forests, (b) 
deciduous forests, and (c) bamboo jungles. The evergreen forests 
are further subdivided into (1) “ kuppalee ” (Mimusops indica) 
forests and (2) mixed forests ; and these are associations. 
In his account of the forest and other vegetation of Pegu, Kurz 
(1875) divided the vegetation of that region into evergreen forests, 
deciduous forests, bamboo jungles, savannahs, natural pastures, 
