130 
THE AMERICAN WATER WEED. 
once developed those remarkable powers of increase which have 
since attracted the notice not only of botanists, but of everyone 
who for any purpose whatever had any interest in the water- 
courses or ponds of our country. The following chronological 
account of published references to its first appearance and spread 
in various districts will probably convey the best idea of what 
that increase has been :— 
1817 
; 1836 
\ 1866 
( 1843 
1848 
1848 
1850 
1850 
N. BRITAIN. 
1851 
CENTRAL ENGLAND. 
A. 
-_ 
oo 
> 
nu 
RIVER CAM. 
( 1852 
FEN DISTRICT. 
San 
ProF. OLIVER says probably first introduced—no locality or 
authority given. 
Waringstown, County Down, Ireland—Mr. JoHN DEw. 
«¢ Still local in Ireland ”—Cybele Hibernica. 
Dunse Loch, Dunse Castle, Berwickshire ; ‘‘In profusion, in Loch 
only ’’—Dr. JoHNSTON, Berwick-on-Tweed. 
Stream from Dunse Loch, “ few tufts.’’ 
River Whiteadder (from above), ‘‘ abundant.” 
“« Whiteadder almost choked with it; had to be dredged to free 
Gainslaw Bridge.” 
“Tweed so full of it as to be a serious hindrance to salmon 
fishers.”” 
“‘ Dunse Loch entirely free of it—supposed swans had eaten it, as 
they followed it down to the Whiteadder and Tweed, deserting 
the Loch entirely””—Miss PRATT. 
Reservoir adjoining Foxton Locks, in canal near Market Har- 
borough, Leicestershire, ‘‘in considerable abundance, matted 
together”’—Miss KirBy. 
Specimens sent by Miss KirBy to PROF. BABINGTON, who 
described and figured it in the ‘‘Annals and Magazine of 
Natural History,” in February. 1848. 
River Lene, near Nottingham (tributary of Trent), ‘“ 1-4th mile 
mass ’’—Mr. J. MITCHELL. 
Watford Locks, Northampton, ‘very abundant ”’”—Mr. KIRK. 
Lockman and labourers said had been so for twenty years. 
Trent and Canal, Derbyshire and Staffordshire, ‘‘ abundant ” 
Mr. BRowN. 
Warwickshire, near Rugby, “ greatest abundance ”—Mr. KIRK. 
Trent, Burton-on-Trent, “Bids fair to block up one of the two 
streams into which the Trent here divides’—RrEv. W. M. 
HIND. 
Specimen sent from Foxton Lock by Miss Kirsy planted by 
PRoF. BABINGTON in tub in Botanic Garden, Cambridge. 
Specimen from tub planted in the conduit stream by Mr. MuRRAY, 
Curator. 
Plant had spread and hidden the stick with which it was marked 
in the conduit stream. 
«‘ Had spread from conduit stream into River Cam, which it had so 
completely choked as to raise the water-level several inches ; 
obstructed docks, sluices, water-courses, and drainage; quite 
prevented fishing, swimming, or rowing, and greatly hindered 
the towing of barges.’’ 
First invaded the Fen District, and in a few years so choked up 
the dykes as to seriously impede drainage by raising the 
water-levels. Mr. RAWLINSON in consequence sent down 
by Government to advise as to best means to counteract the 
danger. Dredging out, &c., tried, without avail; and finding 
all artificial means for eradication of no avail, it was finally 
decided to try would it after a while diminish in quantity, 
which it was found to do in a few years. Not now looked 
upon as a source of danger. 
