Over the greater part of the county the soil is the result of the decomposition of the foregoing superficial formations; and is consequently in most cases of a stiffer and more clayey character on the hill-tops than in the valleys, where it frequently forms only a bed of a foot, or even less, in thickness above the sharp, running gravel. Everywhere in the Chalk districts the soil contains a vast number of flints; but it is, nevertheless, admirably adapted for corn-growing, and especially for malting-grain; Hertford being one of the four English counties best suited to crops of the latter nature. On many of the unenclosed commons the soil is, however, of a poor and hungry nature, producing various kinds of inferior grass, together with spring-flowering gorse, as on Harpenden Common, or heather, as at Kingsbourn Green, between Harpenden and Luton, and at Gustard Wood, near Wheathampstead. On the higher Chalk Downs near Dunstable and Royston there is little or no soil properly so-called; the short, but sweet and nourishing grass growing on the chalk itself. A very different type of soil obtains in the London Clay area in the south and east of the county; this being heavy and clayey, and thus better suited for grass than for corn; in fact in the old days the Middlesex portion of this district was known to the country people as the “Hay-country.” Along many of the river-valleys peaty soils of a marshy and swampy nature prevail.
[7. Natural] History.
In former days, when the mammoth or hairy elephant, the extinct woolly rhinoceros, and the wild ox, together with the African hippopotamus and spotted hyaena roamed over the Thames valley and afforded sport to our prehistoric ancestors, England was joined to the Continent across what is now the English Channel; so that the animals and plants of the southern portion of our islands, at any rate, were more or less nearly identical with those of France and Belgium. The advent of the great ice age, or glacial period, caused, however, a vast disturbance of the fauna and flora (as the assemblages of animals and plants characteristic of different countries are respectively termed), especially as about this time there occurred several oscillations in the level of our country, during one or more of which Great Britain was temporarily separated from the Continent. How much or how little these and other changes had to do with the poverty of the British fauna as compared with that of the Continent is too long and difficult a question to be discussed in this place; but certain it is that even the southern counties of England do possess fewer species of animals and plants than France or Belgium; that this poverty increases with the distance from the Continent; and that Ireland is much poorer in species than England. It may perhaps be well to add, although it does not really concern our subject, that there appears to have been another land-connection by means of which Scotland and Ireland received a portion of their faunas from Scandinavia by way of what is now the North Sea.
Six Hills, Stevenage (Danish Barrows)
At the date of the final insulation of Great Britain from the Continent there is every reason to believe that all the land animals of the former were identical with species inhabiting adjacent regions of the latter. And even at the present day, when isolation has for centuries been exerting its influence on the non-migratory (and in some degree also on the migratory) animals, there are no species of quadrupeds (mammals), birds, or reptiles absolutely peculiar to our islands, with the exception of the grouse; and in the opinion of many naturalists that bird should be regarded rather as a local variety or race of the willow-grouse of Scandinavia than as a distinct species.
Minor variations, however, characterise many, if not indeed all, of our British quadrupeds and birds when contrasted with their continental representatives. The British squirrel is, for instance, very markedly distinct from all the continental races of that animal in the matter of colouring, while somewhat less decided differences characterise our badger, hare, field-mice, etc. Similarly, among birds, the British coal-tit is so decidedly distinct from its continental representatives that it is regarded by some naturalists as entitled to rank as a species by itself; and minor differences from their continental cousins are displayed by the British redbreast, bullfinch, great titmouse, and many other resident species. Indeed, if careful comparisons were instituted between sufficiently large series of specimens, it is almost certain that all species of resident British land animals, as well as exclusively fresh-water fishes, would display certain differences from their foreign representatives; while in some instances, at any rate, as is already known to be the case in regard to certain species, more than one local race of an animal may exist in our own islands.
It is, however, a question as to what is to be gained by the recognition of such comparatively trifling local differences in animals (and still more by assigning to them distinct technical names), as the splitting process may be carried to an almost endless degree. A large London fishmonger is, for instance (as the writer is informed), able to distinguish a Tay from a Severn or Avon salmon; while a wholesale game-dealer will in like manner discriminate between a Perthshire and a Yorkshire grouse. In like manner a Hertfordshire badger or stoat may be distinguished from their Midland or North of England representatives; but it is difficult to see in what respect we should be the better for the recognising of the existence of such differences.
Accordingly, the fauna and flora of Hertfordshire may be regarded for all practical purposes as more or less completely identical with that of the south-east of England generally; and nothing would be gained, even if space permitted, by giving lists of the species which have been found within the limits of our county.