12 
Now at first sight one would suppose a quiet Lake in Scot- 
- land beyond the reach of sophistication ; but Dr. Jonnston 
informs me that aquatic plants have been introduced into that 
piece of water from the south. Were then we have evidence 
of the probability of the Anacharis being an introduced plant 
at Dunse. Then we learn that, six years after, it was found 
in the Whiteadder, between the Lock at Dunse and the sea; 
and now in August, 1852, Dr. JoHNnsTon writes to me thus: 
* As with you, so with us, the weed is altering the character 
of the Whiteadder, and will require before long to be dealt 
with as we have dealt with savages in some places.” Its 
second discovery was in the Foxton Locks, situate on the 
Union Canal, which connects Market Harborough with 
Leicester, and the river Welland with the Soar and (through 
the Soar) with the Trent. When therefore it was found in 
the Lene, near Nottingham, it should be remembered that 
it was in a part of the same water system, Afterwards, it 
was found in the Locks at Welford and Watford, near 
Northampton; but these points are within a very short 
distance of each other, and both are on the same line of canal 
as the Foxton Reservoir. In 1849, it was found in the canal 
near Burton-on-Trent, and in the Trent River; but these 
points, although in two new counties, were all in water com- 
munication with the previous stations ; and again,.when it was 
found ins Warwickshire, near Rugby, and in the Oxford 
canal, these are within ten or twelve miles of the Watford 
Station, and on the same line of canal. These several Midland 
localities may therefore be regarded virtually as but one, 
because the Anacharis, when once introduced, would, in a 
few years, inoculate any connected water system from one 
end to the other.* 
ri 
* Ido not deem it necessary to refer to the Sussex and Yorkshire stations, 
— it is admitted that in these places the weed has certainly been intro- 
