QUERIES IN LOCAL TOPOGRAPHICAL BOTANY. 
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QUERIES IN LOCAL TOPOGRAPHICAL BOTANY. 
Part II. 
BY MR. T. R. A. BRIGGS, F.L.S. 
(Read February 15th, 1883.) 
In a former paper I endeavoured to show that the investigation of 
local phenomena may be undertaken with a view to the solution of 
scientific questions of the utmost importance and greatest magnitude; 
that evidence supplied by local facts may be used to support or 
weaken, possibly to prove or disprove, some of the startling 
theories of the age. Among the matters that I touched on were 
the differences between species and varieties, species competition, 
the respective influences of climate, lithology, and geology on plant 
distribution, and hybridism. These subjects were all suggested by 
facts belonging to certain species growing within the counties of 
Devon and Cornwall. The last plants under review were certain 
Epilobia, belonging of course to the order Onagracece. I proceed 
to say a little about two plants of the succeeding one of Halora- 
giacecs. They are Myriophyllum spicatum, L., and M. alter niflorum, 
D.C. The distribution of these two needs fuller working out. At 
present the probability is that some of the older records standing 
under the name of the former will have to be transferred to the 
latter, they having been made before the species were discriminated 
from one another. Both occur in the area of the Flora of Ply- 
mouth, but so far as I have seen very rarely produce flowers. 
Ponds and still waters are not numerous in this hilly part, and the 
rapidity of the rivers and streams generally in Devon and Cornwall 
seems to prevent the Myriophylla plants in them from bearing 
flowers. That it is this force of flow which hinders another 
hygrophilous species, Ranunculus penicillatus, Hiern., from pro- 
ducing flowers near Plymouth was well-nigh proved to me in the 
spring of 1880, by a few flowers making their appearance when 
the quantity of water in a stream where it occurs had become less 
