XXL FLORA OF OXFORDSHIRE. 
Mr. Stacey calculated its dry weather summer flow between 
Wolvercote and Wytham was 11620 cubic feet per minute 
Its dry weather winter flow 22624 5 a 
Rainy weather winter flow 35498 ” ” 
During floods, winter flow 70996 6 
As the catchment basin of the Cherwell is aaons as great 
as that of the Thames above Wolvercote, i.e. about 600 square 
miles, these figures may be doubled for the amount passing 
Iffley. 
At Oxford the Thames is joined by the Cherwell, which rising 
at a summit level of about 450 feet in Northamptonshire receives 
in its southern course many small tributaries; at Dorchester 
the Thame rising at about 450 feet enters the Thames, which 
then receives no other important stream from Oxfordshire in its 
southern course. 
The Ouse rises in Northamptonshire, and only drains a 
small tract of north-east Oxfordshire. 
The Stour drains a still smaller tract of north-west Oxford- 
shire, which is the only portion of it belonging to the Severn 
basin. 
BOTANICAL DISTRICTS.’ 
Based upon the river drainage these are as follows :— 
(1) The Stour district of the Severn drainage. 
(2) The Ouse Fr 3 Ouse % 
About nine-tenths of the county is in the Thames drainage 
which we may divide into— 
(3) The Swere or Upper Cherwell district. 
(4) The Ray or Lower . 
(5) The Isis or Upper Thames, inelading the Windrush and 
Evenlode, and the main stream north of Oxied: 
(6) The Thame or Mid-Thames, including the main stream 
of the Thames from Oxford southwards to Mongewell, and the 
country north of the lower Chalk. 
(7) The Thames or Lower Thames, including all the county 
south of the Upper Greenstone formation. 
Berkshire localities are inserted for the use of Botanists 
living near the border and are principally chosen from the 
Oxfordshire side of the county. When the plant occurs in the 
