294 CULTURE OF FARM CROPS. 



abundant space to grow in, we find that the bulb is ter- 

 minated by small rootlets which proceed from many parts 

 of its under surface, but chiefly from the tap or central 

 root and its immediate vicinity. These rootlets, if allowed 

 freely to develop themselves, are remarkable not only from 

 their number but for their length and the fineness of their 

 texture. The seed bearing to the ultimately developed 

 root the proportion of 1 to 1,000,000, it will be readily 

 understood that the bulb has to draw from the soil and 

 from the atmosphere an enormous amount of material; 

 from the soil it draws this material by means of the root- 

 lets, from the atmosphere by means of its leaves. The 

 rootlets, therefore, should have an abundance of soil space, 

 and not only this, but the soil must be of such a friable 

 character as to enable these tender rootlets to pierce easily 

 into and pass through it. Hence we deduce that the 

 bulbs should not be too near each other; and secondly, 

 that the soil should be highly cultivated, porous, and 

 friable in good tilth, as it is termed. Of the necessity 

 there is for giving ample space between the plants we shall 

 hereafter give abundant proof. By securing this ample 

 space the rootlets have leave to spread laterally, while, by 

 the depth of soil, they are allowed to descend vertically. 



93. A remarkable feature of the turnip as compared 

 with a grain plant is the development of its leaves. By 

 the size of the leaves and the green colour they present, 

 we judge of the healthiness of the turnip crop. The 

 leaves enable the plant to draw much of its nourishment 

 from the atmosphere. 



94. The place of the turnip crop in the rotation is 

 always between two cereal or grain crops, and is the crop 

 which receives the heaviest manuring. In the four-course 

 rotation it follows the wheat and precedes the barley. By 

 means of its leaves it draws much, or is supposed to draw 

 much, of those constituents which are most beneficial to 

 the succeeding grain crops ; while, from the habits of its 

 growth, it permits of a large amount of care being expended 

 upon the cleaning of the soil in which it grows, and the 



