HYDROCHARIDACE. 83 
tion from the American continent. Almost at the same time other observers disco- 
yered the plant in various situations, having had their attention drawn to it by Mr. 
Babington’s paper. Dr. Johnston found it in two places in the Whitadder River. 
“Mr. James Mitchel writes that in the Lene, a tributary of the Trent, near Nottingham, 
at was “growing in great profusion for about a quarter of a mile in extent.” In 
November of the same year it was found in Northamptonshire, in the Watford Locks, 
by Mr. Kirk, in great abundance. He considered it to be an introduced plant at that 
time, but afterwards changed his views, from its simultaneous discovery in so many 
other localities. All his specimens were female, and growing in such dense masses 
that it was with difficulty good-sized specimens could be detached, from its extreme 
brittleness. Mr. Kirk was informed by the lock-man that the plant was quite as 
abundant when he first came to the lock five years before, although the reservoir had 
been cleaned out once or twice during that period. The lock-man further stated that 
he had formerly resided at Foxton Locks, and that the reservoirs there were full of it 
“more than twenty years back ;” also that it had been plentiful in the Market Har- 
borough Canal during the whole of that period. A short time after this conversation 
took place two labourers belonging to the lock came up, and both of them confirmed 
the statement of its being plentiful in the Market Harborough Canal, and one of them 
added that the ‘‘ Welford Branch,” a narrow canal comparatively little used, was so 
full of it that “the passage of boats was impeded, and the canal necessitated to be 
cleared out once or twice a year, and that it had been so for many years.” Mr. 
Marshall believes there was some mistake here, and it is well to remember that the 
evidence of persons unaccustomed to observe is of very small value in natural pheno- 
mena. The plant seen by the lock-men may have been altogether a different species, 
but that it was a fast-growing water-weed would be enough to account for their con- 
fusion. Scientific data are founded on the observations of competent witnesses 
only. In August 1849, the Anacharis was found in Derbyshire and Staffordshire 
by Mr. Edwin Brown, growing in profusion in the Trent. He was convinced that 
the plant was new to that locality. All the plants were female. In Christmas 
1850, it was found by Mr. Kirk in Warwickshire, near Rugby, in the greatest abun- 
dance; and in July 1851, by the same gentleman in the Oxford Canal, near Wyken 
Colliery. The Rey. W. Hind, writing from Burton-on-Trent in July 1851, describes 
the plant as having greatly increased in eighteen months, and says “it bids fair to 
block up one of the two streams into which the Trent here divides.” In 1851 Mr. 
Marshall and others noticed the plant in the river between Ely and Cambridge, but 
not in large quantities. Since then it has increased so rapidly and wonderfully that it 
has become the greatest source of annoyance to all watermen, and navigation seems 
almost to be arrested by it. Sluice-keepers complain that masses of it get into the 
pen, and retard the operation of letting boats through very greatly. The railway 
dock at Ely became so choked with it recently that several tons of it had to be lifted 
‘out. Rowers complain sadly of it, and the University oars find it so prejudicial to 
their progress, that, civing their Professor of Botany the credit or blame of intro- 
ducing it into their river, they called it Babingtonia pestifera.* Besides the annoyance 
that this weed is to boatmen and fishermen, the drainage is considerably impeded by 
it, and it is therefore a question of great importance as to how its rapid increase can 
be arrested. The arguments for the origin of this plant in our rivers, or in those of 
> 
* Professor Babington did not introduce it at Cambridge. See p. 84, line 24, ef 
seq.—HEp. 
* 
Mm 2 
