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HINTS AND NOTES 



and most of the cornfield weeds, are essentially 

 southern plants, hence they will not grow 

 where northern plants are quite at home. 



Soil, altitude, and climate are the three 

 essential factors for plant growth ; the first is 

 especially important in determining the dis- 

 tribution of cereals. The best soil is a loam 

 or clay, with some proportion of silica or sand. 

 Calcareous soils and marl, which contains up 

 to 25 per cent of lime, are also suitable. 

 Sandy and siliceous soils are in general too 

 dry or close, or barren in alumina. Rocky 

 districts, such as those of Scotland, and high 

 hills in England and Wales, are better suited 

 for oats, but even here this crop does not 

 flourish beyond a certain altitude. The lime- 

 stone massifs of the Pennine Chain are also 

 too bare and lacking in deep soil for cereals. 



Altitude, however, governs the distribution 

 of cereals mostly, for with increase in altitude 

 there is increase in rainfall, and this is dele- 

 terious. Watson established a zone, the 

 Agrarian zone, up to 1000 ft., above which 

 cereals do not usually grow well. Climate, 

 again, has the same effect as altitude, and for 

 this reason the south and east of England 

 and Scotland are best suited for cereals. The 

 N. and W., and the whole of Ireland, are too 

 moist and wet as a whole. 



Arable Land Mainly Confined to Lowlands. 

 Apart from the limits of cultivation owing 

 to altitude, there are some considerations 

 which tend to confine the distribution of the 

 cereals, and hence cornfield plants, as a rule, 

 to the lowlands. 



In the first place the lowlands as compared 

 with the highlands are far more easy to culti- 

 vate. For in the plains the surface is more 

 level, and ploughing and kindred operations 

 are less arduous, though the slopes of many 

 uplands, as on the chalk, are often given up 

 to cereals. But on the chalk as on other hilly 

 tracts the soil, owing to denudation, rain 

 wash, &c., is very shallow, and the ground 

 becomes more and more stony the more it is 

 tilled. Hence the lowlands offer better condi- 

 tions, for almost universally they possess a 

 deep soil. 



Another and very important reason is that 

 the lowlands as a rule are more closely con- 

 nected with the main systems of railway, 

 canals, &c., and transit is easier. 



Another reason is the better drainage of the 

 lowlands. River systems form a natural drain- 

 age for the plains, and artificial drainage also 

 is more readily applied, being impossible in the 

 uplands, save for the natural fall of the surface 

 waters by gravity, its distribution and direction 

 being difficult on hill slopes, as the occurrence 

 of springs shows. In valleys, too, there is a 



natural alluvium, and the river gravels, which 

 are especially suited to light and early crops, 

 are made use of by the agriculturist who knows 

 the local geology. 



Difference between the Plants of the Hedges 

 and Furrows. The cornfield as a complete 

 whole is a composite type of vegetation. 

 Apart from the portion of each field under 

 cultivation, there is usually a grassy strip 

 along the borders, varying in width according 

 to circumstances, and in some cases as exten- 

 sive as the grass rides in a wood. Beyond 

 this zone or border conies, as a rule, a ditch 

 with banks on either side. Then there are 

 also the boundary hedges in most districts, or 

 in some areas dykes or ditches alone, with no 

 other boundary, and in the north of England, 

 Wales, and Scotland, stone walls. 



Each of these extensions or limits to the 

 cornfield is of particular importance in study- 

 ing a cornfield flora, and special attention 

 should be devoted to them. For not only do 

 they form a transition from the grass-field type 

 of vegetation upon which they abut, but they 

 also serve in the case of the grass fringe to 

 stabilize the cornfield flora, and in the case of 

 the ditch and hedge to retain certain of its 

 constituents. The weeds that can subsist 

 under such conditions (more intense than on 

 the open ground of the cultivated area) are 

 thus selected as the dominant and sturdier 

 types, e.g. White Campion and Hemp Nettle. 



The Affinity of Cornfield Plants for Waste 

 Ground. The soil conditions of the cornfield 

 exhibit a striking similarity to those of the 

 waste place and kindred habitats. It might 

 be in some ways better to combine the two. 

 But there is in the first place a greater simi- 

 larity between the character of the meadow 

 and the cornfield, the origin of which is the 

 same; and in the second place there is a 

 marked difference between the character of 

 the cornfield and all cultivated land, and that 

 of the waste place. For in the former certain 

 definite operations are continually going on 

 which are responsible very largely for the as- 

 sociated cornfield wild plants, whilst the very 

 nature of the waste places, and the absence of 

 any such operations, renders such habitats 

 entirely lacking in the chief characteristics 

 that distinguish cultivated land from all other 

 types. 



None the less the essential connection be- 

 tween many descriptions of waste place asso- 

 ciated with farming causes the flora of the two 

 to be essentially similar. For there is, in the 

 first place, a continual carting of materials 

 from the cornfield to stackyards and similar 

 storage areas, when seeds are being continu- 

 ally dropped or dispersed, so that their range 



