On the Origin und Distribution of the British Flora. 81
stream (name ?) from North Weald, then flows south-west to
Chigwell and Woodford, and finally south-east past Ilford
into the Thames at Barking Beach. Near Ilford it receives
two streams from Hainault Forest, the upper of which seems
to bear the name of Aldersbrook. The entire course of the
Boding is stated by Gibson as 37 miles, and by the Ordnance
Survey as 33 miles, the area it drains being 317 square miles.31
The Pym or Bourne rises at Stapleford, flows past Havering-
atte-Bower, Romford, and Dagenham, into the Thames at
Halfway Beach. Next come three streams of doubtful
nomenclature. One flowing west of Upminster and Barnham
is marked "Ingreburn" in the 'Encyclopaedia Britannica';
the second flows from between North and South Ockendon to
the east of Rainham ; and the third flowing from Thorndon
Hall to Stifford and Purfleet is marked Ingrebury in Mr.
Gibson's map, but flows past a hamlet named Childerditch.
The name Ingrebourne probably belongs to the last. The
River Roach, made up of streams from Hadleigh and Prittle-
well and from above Rochford, flows mainly between Foulness
and Wallasea Islands. Its basin, with that of the Crouch,
includes 181 square miles. The latter river rises near Little
Bursted, less than three miles from the sources of the Childer-
ditch stream and the Wid, a tributary of the Chelmer, and
flows eastward, having a course of 15 miles. It is doubtful
if the name Blackwater is properly applied to more than the
estuary of the great series of streams which drain 434 square
miles out of the 1648 which Essex contains. In accordance
with this view, the Ordnance Survey gives it a length of only
6 miles, as against Mr. Gibson's 46. The stream which rises
near Wimbish, and runs by Bardfield and Shalford to Pan-
field, ought, at least so far, to be known as the Pant.
According to the best local authorities the stream should not
be called Blackwater until it reaches the village of that name,
half-way between Coggeshall and Braintree. The Survey
gives the length of the Pant as twenty-eight miles. Below
Kelvedon Mill, the Blackwater receives a stream there known
31 [It may be remarked that the name of the river is always spelled
"Rhodon'' in Warner's 'Plantae Woodfordienses.'—Ed.]
K