QUERIES IN LOCAL TOPOGRAPHICAL BOTANY. 
117 
QUERIES IN LOCAL TOPOGRAPHICAL BOTANY. 
LECTURE BY MR. T. R. A. BRIGGS, F.L.S. 
(Read January 26th, 1882.) 
I desire in this paper to direct attention to some remarkable cases 
of vegetable distribution within the two counties of Devon and 
Cornwall, and intend, in speaking of these striking facts in the 
local flora of the present day, to hazard some conjectures as to the 
causes which have produced them. If at present local investi- 
gations turned more on such matters, and students of nature would 
try to trace out the influences which have been at work in their 
several neighbourhoods in past ages by noticing those at present 
active around them, each might in his little sphere of labour, and 
in proportion to his measure of industry and ability, help on the 
great scientists of the day in bringing forward theories capable of 
demonstration and unassailable because founded and built upon the 
sure ground of honest and clearly-ascertained facts. In preference, 
however, to undertaking investigations of the kind indicated, many 
employ their time in writing of evolutionary stages through which, 
according to their imaginings, species, such as we see them, must 
have passed to attain their present forms and characteristics. 
Some species belonging to the order Caryophyllacece are so 
peculiarly distributed in Devon and Cornwall that it is well worth 
while to gather particulars as to their respective ranges, whilst in 
the genus Silene we find two plants — Silene inflata, Sm., and S. 
maritima, With. — possessing so much in common as to show the 
difficulty there often is in defining a species, as opposed to a variety. 
They afford occasion for a few remarks bearing on the question as 
to the fixity or otherwise of species. The two, generally regarded 
at the present day as distinct, would by their many points of re- 
semblance suggest to some the possibility of the maritima being 
only a modified form of the inflata — both descendants from but one 
VOL. VIII. h 
