which entirely replaces (Œ. Phellandrium in the district. The water buttercups include Ranunculus heterophyllus, R. divaricatus, R. peltatus, R. fluitans, and the pondweeds are Potamogeton natans, P. Friesii, P. interruptus,P. pectinatus, P. zostertefolius, P. pusillus, P. crispus and P. densus, but P. polygonifolius and P. alpinus appear to be absent. The canal gives the sedges Carex paniculata, C. acuta, Eleocharis acicularis; and the meadow crane's-bill (Geranium pratense) is a not uncommon plant near the Ouse. There are few marshes or bogs from a botanical point of view, since the undrained portion although wet is singularly poor in uliginal vegetation, and is represented by such mesophytes as Carex vulpina and C. flacca, Galium palustre, Glyceria plicata and G. fluitans, Apium nodiflorum, Juncus lampocarpus and J. glaucus.
There is a very small marsh near Winslow of a very different character, since it resembles the rich marshes which occur at Headington in Oxfordshire and at Cothill and Hinksey in Berkshire. As drainage has been already begun, it is probably doomed to disappear in the not distant future. In it I was enabled to notice for the first time as plants of Buckinghamshire the black bog-rush (Schaenus nigricans) and the rush (Juncus obtusiflorus), and also the following interesting species, the butterwort (Pinguicula vulgaris), the marsh helleborine (Epipactis palustris), the marsh thistle (Cnicus pratensis), the sedges Carex pulicaris, C. flava, C. Goodenowii, C. panicea, C. Hornschuchiana, the bog pimpernel (Anagallis tenella), the fragrant orchid (Habenaria conopsea), and the bee orchid (Ophrys apifera), the latter in an unusual station; the milk-wort (Polygala vulgaris), the bedstraw Galium uliginosum, while in close contiguity in a gravelly field grew the upright form of the soft clover (Trifolium itriatum var. erectum) and the chickweed (Cerastium arvense). The railway banks near Swanbourn have the zig-zag clover (Trifolium medium), and in the brickyard near there are some very fine examples of Lotus tenuis.
On the railway banks near Hanslope there is a very abundant growth of a hawkweed, a native of eastern and central Europe, namely Hieracium preealtum, and near it is another plant which is either a hybrid of that species with H. Pilosella, or possibly H, pratense. Some short distance away the yellow chamomile (Anthemis tinctoria) is also abundantly naturalized for a considerable distance, and nearer the border of Northamptonshire the gold of pleasure (Camelina saliva) is plentiful, and other aliens such as Caucalis latifolia, Salvia verticillata, Bromus arvensis and B. squarrosus, Chenopodium ficfolium and others have been found.
At Castlethorpe the calamint (C. parvifolia) occurs, but it may be possibly a relic of cultivation as it grows near Castle Close. Here too the fiddle dock (Rumex pulcher) and the grass Poa compressa occur, and near Hanslope I added Carex pendula to the county many years ago. Near Olney, where the limestone comes to the surface, the gypsophilous grass Brachypodium pinnatum so abundant on the oolite in Oxfordshire, but so rare in this county, is found. From Lavendon the wild everlasting pea (Lathyrus sylvestris) has been recorded, and the grass-leaved pea (L. Nissolia) is found near Wavendon.
2.The Ouzel District
which is also in the main drainage of the Ouse, is so named from a small stream whose sources are chiefly in the Dunstable Downs, one issuing from the chalk near the Beacon Hill between Ivinghoe and Edlesborough, another near Pitstone Green, and there are several other feeders from the Cretaceous rocks. Another tributary comes from the high ground of Cublington and Stewkley (496 feet) and joins the chalk streams to the south of Leighton Buzzard, between which place and Fenny Stratford it is reinforced by several streams coming from the western side of the hills of Stewkley North End, Drayton Parslow and Mursley, while on the east side the rich district of Brickhill and Woburn Sands also drain into it. A small brook which rises in Bedfordshire near Ridgmount, and passes through Salford, Milton Keynes and Broughton, joins the Ouzel near Willen, and the Ouzel itself shortly after enters the Ouse near Newport Pagnell.
The district is contained within the following limits: Starting from the place near Great Linford station, where the Grand Junction Canal is near the Ouse, the separating line from the Ouse district, which has been already described, passes from Newport Pagnell to the Bedford county boundary at Broad Green, which is near North Crawley, following the county boundary in a southernly direction to Wavendon, Linslade, and then by Edlesborough to Little Gaddesden, where Hertfordshire takes the place of Beds, and the limit is the boundary of that shire in its eccentric and arbitrary separating line, as it is traced across the Chilterns. The boundary of the Ouzel district passes by Aldbury to the main line of the London and North-
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