In regard to fishes, it is of interest to quote the following passage from Sir Henry Chauncy’s _Historical Antiquities of Hertfordshire_, published early in the eighteenth century. After referring to its other fish, it is there stated, in the author’s quaint language, that the river Lea also contains “some Salmons; which (like young Deer) have several denominations: the first Year they are called Salmon-smelts, the second Year Salmon-sprats, the third Year Salmon-forktails, the fourth Year Salmon-peall, the fifth Year Salmonets, and the sixth Year Salmon; and if these Fish had free Passage by the Mills, and thro’ the Sluices at Waltham up the Stream towards Ware and Hertford, where they might Spawn in fresh Water and were carefully preserved from Pochers, they would greatly increase in that River, and be of great benefit, as well to the City of London as the Country; for some Water-men have observed, that they delight in this Stream, and play much about those Sluices at Waltham.” Chauncy likewise mentions that trout from the Lea below Hertford, where it has peaty banks, are much less red than those from the gravelly streams of the chalk districts. For botanical purposes the county has been divided into six districts corresponding to the river-basins; the first two belonging to the Ouse system, and comprising the Cam and the Ivel basins, and the other four, comprising the Thame, the Colne, the Brent, and the Lea, pertaining to the Thames system. Of these the Lea area is the largest, the Colne next in size, the Ivel considerably smaller, and the other three quite small. In some respects the local characters of the flora are, however, better brought out by taking the geological formations as a basis of division. The Upper Chalk area, capped with much Boulder-clay on the eastern, and with clay-and-flints and gravel on the western side, corresponds very closely as regards these divisions with the Lea and the Colne basins. The Middle Chalk, which as we have seen is exposed on the flanks of the continuation of the Chiltern Hills in the north-west, is peculiar in being the only area in the county in which grows the pasque-flower, or anemone; this chiefly flourishing on south-westerly slopes, as at Aldbury Towers, near Tring. The Middle Chalk is also the chief home of the various kinds of orchis; the dwarf, the man, and the butterfly orchis being apparently restricted to this formation. The Tertiary area has a vegetation of a totally different type from the so-called “dry-plant type” characteristic of the Chalk area, but it cannot be further mentioned here.