106 DR. HOOKER AND DR. THOMSON’S PRECURSORES / 
/ 
Precursores ad Floram Indicam.—Balghminee. By J. D. Hooker, 
M.D., F.R.S., L.S. &c. and T. Toomson, M.D., F.R.S., L.S. &c. 
[ Read June 16th, 1859.] 
Tuis Order, as is well known, attains its maximum development 
in India, and it there presents a vast assemblage of forms, all but 
one of which strictly belong to the genus Impatiens. 
It is often the case that when a genus is in a striking degree 
local, its species are to а considerable extent well marked and 
easily defined: such, however, is not the case with Impatiens ; for 
it would be difficult to indicate another genus in the vegetable . 
kingdom, presenting amongst its species so many and such different 
modifications of structure, and of which the species are so univer- 
sally and so excessively prone to vary. 
We commenced the study of the genus several years ago, with 
nearly 100 species, fully 2000 good specimens, from all parts of 
India, and engravings or original coloured drawings, with analyses, 
of upwards of fifty. Оп surveying these materials for the first 
time, we were struck no less with the prominence of the natural 
groups into which most of the species appeared to arrange them- 
selves, than with the marked contrasts in the form and colour of 
the floral organs of many of the species ; and the accessibility and 
apparent feasibility of these characters were so obvious, that we 
eongratulated ourselves on the prospect of making natural and 
well-defined groups of the majority of the species at any rate. А. 
little further examination of these seemingly objective groups 
sufficed to dispel the illusion; and after three different earnest 
attempts to master the genus, at intervals of several years, and 
with the aid of many more specimens received since we commenced 
the task, we have now just risen from what must be for the present 
the final effort, with a feeling of great dissatisfaction with the 
results obtained, whether as to grouping or limiting the species. 
There are only two obvious and well-limited divisions of Zmpa- 
tiens :—1. The Scapigere, with tuberous perennial rhizomes (appa- 
rent roots), from which all the leaves immediately spring, and 
long scapes with short terminal racemes of flowers ; and 2. The 
Caulescentes. Were both these divisions comprehensive, the 
facility of recognizing them would have materially aided the 
systematic study of the species; but it is not so: the acaulescent 
consists of five (or perhaps but three good) species, and is so 
singularly confined in geographical area (the western peninsular 
