272 



THE TUENIP CROP. 



bourhood, and therefore demand the most scrupulous care 

 on the part of the seedsman, that no two varieties are 

 allowed to flower near each other. If that happens, 

 hybrids are immediately produced, and purity of race 

 becomes impossible. It is also to be borne in mind, that 

 the smaller the patches of any c Brassica ' in flower, the 

 greater the chance of its being spoiled by insects, which 

 frequent it after leaving neighbouring fields, containing 

 other species of ' Brassica ' also in flower." 



Our subject now is Turnips, and consequently we have 

 only to refer to two out of the five divisions the ordi- 

 nary turnip bearing the same relation to the rough-leaved 

 Rape (Brassica rapa) as the Swedish turnip (ruta baga) 

 does to the smooth-leaved Rape (B. campestris). They 

 appear to be only varieties of their respective stocks in- 

 duced by cultivation the originals being marked by 

 their more erect habit of growth, and by their small, fusi- 

 ng, i. form, and fibrous roots; while the 

 more lowly and spreading growth of 

 the turnip, and its largely developed 

 globular root (napiform), at once mark 

 the changes resulting from a long and 

 careful cultivation. 



The Swedes are usually known by 

 the colour of the top of the bulbs, such 

 as purple, green, or purplish-green. Of 

 each of these there are several varie- 

 ties in cultivation. Lawson 1 enumer- 

 ates and describes five of the purple, 

 three of the green, and six of the pur- 

 plish-green top Swedes. 



Common Purple-top or Lothian 

 variety (fig. 1) is that in general cultivation in the north, 

 and is the stock from which most of the others have 



1 Synopsis of Vegetable Products, &c. Edinburgh, 1851. 



