l6 AMERICAN VINES. 



of the Rupestris, etc , while Lenoir, Herbemont, Vialla, etc., 

 accommodate themselves much better. We will examine 

 later on all these varieties from this point of view, but will 

 now give the reason for those differences. As it is not 

 sufficient to only observe these facts, we must search for the 

 causes and conditions producing them. This permits us to 

 generalize, and also, frequently, to deduct results of the 

 greatest importance. 



Cazeaux-Cazalt, who made a complete study of the 

 question of adaptation to soil, attributes the differences 

 of vegetation shown by American vines in compact soils to 

 their root structure. 



The Riparia, most of the Rupestris, etc., have a poor root 

 system. The roots are thin and very hard, much ramified, 

 and ending in abundant very fine rootlets. The Lenoir, 

 Vialla, Herbemont, Cunningham, Cinerea, York-Madeira, 

 etc., have on the contrary, much stronger roots and less 

 slender rootlets. The European vine, which grows well 

 everywhere, has also very strong roots. 



Why is it that vines with large roots adapt themselves to 

 compact soils better than others? It is difficult to give a 

 satisfactory explanation. Perhaps it is merely because strong 

 roots have a penetrating force that is deficient in slender 

 roots. 



Whatever the reason is, the fact is constant, and must be 

 taken into account. It demonstrates that American vines, 

 either pure or crossed, having a powerful root system, also 

 Franco-American hybrids, which have, like their French 

 stock, strong roots, ought to develop vigorously in compact 

 soils. Experiments which have continued for several years 

 prove this very clearly. 



(c) Humidity (Moisture}. Humidity has equally an in- 

 fluence on the growth of the vine, although it is not quite 

 so important as was formerly thought. An exaggerated 

 humidity of the soil favours the development of cryptogamic 

 diseases, non-setting, etc., and, besides that action, consider- 

 ably checks the spreading of the root system. 



Vines growing in very damp soil often have very large 

 exterior growth, but the roots, in proportion to the aerial 

 parts, are always weak. This does not apply only to the 

 vine, but is true in the case of nearly all plants. Up to a 

 certain point, the drier the soil the larger the root system, 

 because in those soils it is very likely necessary for them to 



