Primary Woodland and its Derivatives 31 



the neighbourhood, as ultimately of the subsequent progression of the city. 

 These meadows are retained to the present day, as their liability to flooding 

 in winter, and exceptionally even in early summer, precludes their utilization 

 for any other purpose, until the level can be raised (cf. Port Meadow and Osney 

 allotments). 



Further diminution of the wooded-area followed increasing local and urban 

 demands for fuel. Small copses were retained in the agricultural area. Derelict 

 land, too wet on a clay bottom, too dry on upper clay, or too steep on hill-sides, 

 was left to such woodland as it might carry. Broader areas of woodland, long 

 retained as common land, have been enclosed, and now little remains of the 

 original general forest-formation save tracts more or less 'forested' or 'pre- 

 served', as Bagley Wood, VVytham Wood, Stow Wood, and a multitude of 

 minor copses, as marked scattered on the map. The tops of adjacent hills 

 have been largely cleared, although all appear capable of carrying woodland. 

 Cumnor Hurst has been cleared by fire, Shotover mainly by cultivation ; the 

 only suggestively dry hill-tract is the northern end of Garsington Hill, now 

 under arable land, with but few trees in the hedges. 



Residual Woodland, in whatever condition it may have been forested, on 

 land which has apparently never known the plough, may be traced on Oxford 

 Clay in Marley Wood, Wytham, Studley, Stanton St. John, Noke Wood, 

 Water Perry, and Headington Wick ; on Kimeridge Clay in Bagley Wood, 

 Sandford Brake, Brasenose Wood ; on Greensand in Hen Wood ; on Calcareous 

 Grit in Tubney Wood and Stow Wood. 



Origin of Underwood : In high tropical forest of primal order there is 

 no underwood. The canopy is dense, the lofty trees may be wreathed with 

 liana climbers, and gay with high zones of epiphytes, but the ground is bare. 1 

 Following the extension of forest to dry and extra-tropical regions with 

 reduced or seasonal water-supply, the canopy is thinned, and increased 

 competition for water leads to the relegation of many arboreal forms to a 

 lower zone of underwood, as smaller trees, still woody and arboreal in habit, 

 but scarcely worthy of the name of timber-tree, in all degrees of diameter and 

 size of woody stem, to the smallest woody shrubs in the poorer classes of 

 forest. This production of smaller, apparently dwarfed forms, is, however, 

 not entirely a phenomenon of reduction, or mere deterioration of vegetative 

 habit. The latter somatic feature is correlated with an advance in repro- 

 ductive specialization, as these small trees flower and fruit at an earlier 

 stage, giving quicker returns, and so have no need to attain the full size of 

 the older type of tree. It is clear that this idea carried to excess, will 

 give smaller shrubs which may even flower the first year of their growth, 

 and continue to flower and fruit for many succeeding years. Few trees of 

 high forest do this ; the age-limit for flowering being largely determined 

 by the fact that the bulky soma with great root-penetration, at last reaches 

 the limit of balancing its proteid-synthesis with its photosynthetic capacity, 

 beyond which excess carbohydrate becomes a nuisance, and may be elimi- 

 nated in spore-production and the seed-stage. In such case, trees may be 

 said to reach a certain adult phase ; comparatively little growth is added 

 once the fruiting-period is reached, and parasitic seed-stages drain the parent 

 organism of superfluous material. A period of 30-50 years is commonly 

 required by .forest -trees to reach this point, and it is evident that any gain on 

 such a time-limit will prove advantageous in hastening on the race. 



Such small trees and bush-forms become relatively more numerous as 

 the high forest deteriorates ; and hence in northern woods will be abundant. 

 They constitute a characteristic feature of English woodland ; the more so 

 as the flowers may be conspicuous and decorative as insect-pollinated 

 mechanisms of considerable elaboration, or the fruits are gaily coloured and 



1 Sehimper (1903), loc. cit., pp. 288, 298, 301. 



