ADAPTATION. 17 



develop powerful roots in order to search for the water they 

 require. In damp soils, where moisture is plentiful, a small 

 number of weak roots suffice to furnish the water necessary 

 for the life of the plant. 



Excess of water is undoubtedly an obstacle to the success 

 of vineyards. In damp soils vines do not develop their 

 roots, although the branches grow well, and when a sudden 

 intense drought occurs they are not in a position to absorb 

 the necessary water. They wither and die. 



The humidity of the soil may, in some cases, indirectly 

 favour the development of American or European vines. 

 We know for a fact that it is a serious obstacle to the 

 multiplication of phylloxera, as proved by the efficacy of 

 artificial submersions. The humidity of the soil, when in 

 excess, does not act in any other manner. It is a natural 

 submersion It follows, under these conditions, that the 

 resistance of American vines subject to phylloxera is 

 increased. Certain direct producers, such as Othello, 

 Canada, Brandt, Autuchon, etc., little resistant, have a 

 longer life in damp soils. It is also the prolonged humidity 

 during the last few years that has allowed the dying French 

 vines to slightly regain their vigour in the compact clay soils 

 which retained the water, and also in sandy soils. It is this 

 also which has retarded the progress of the phylloxera, and 

 rendered in many cases the insecticide treatments more effi- 

 cacious, so that a part of their action, perhaps the largest, 

 was derived from it. It is to this finally that must be 

 attributed the revival of old vines badly affected by the 

 phylloxera, and not to a particular system of pruning. 



Humidity often acts in concert with compactness. It is 

 the same with regard to the coldness of the soil, which is 

 mostly the consequence of compactness and excessive 

 humidity. In spring it delays the development of the roots 

 and also checks the nutrition of the plants. All vines are 

 not equally affected. Early kinds accommodate themselves 

 better than late sorts. 



(d) Fertility. The fertility of the soil is a very powerful 

 adjunct to the growth of the vine. The more fertile the 

 soil, the larger its development. However, great fertility is 

 not equally necessary to all vines. They have not from this 

 point of view the same exigencies. The V. Rupestris is, 

 perhaps best adapted to poor soils. It attains considerable 

 dimensions, and carries very fine grafts, when other varieties 



