10 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. 



Vitis monticola. This vine has only a limited range of distribution 

 in Texas, where it is found on lands similar to those where the Rupes- 

 tris grows, but containing generally a high percentage of lime. It comes 

 next to the Berlandieri as a resistant to chlorose, which is caused by 

 excess of lime in the soil. This stock is a very good element in hybrid- 

 izing, and may turn out to be very valuable as a direct grafting stock. 



Vitis calif ornica. The wild native vine of California; it has a resistance 

 to phylloxera too low to be of much use. 



Vitis Berlandieri. This vine is found in Texas, New Mexico, and 

 Mexico, growing on limestone ridges, where it resists excessive drought 

 and heat. The quality of resistance to lime would not be of much interest 

 in California, but it may prove to be a very valuable stock in heavy, 

 dry soils, as probably its large fleshy roots will allow it to penetrate 

 readily. Though the Berlandieri does not grow well from cuttings, its 

 hybrids have not that drawback. 



From these few remarks on the principal resistant stocks we may see 

 that the range of adaptation of each variety is rather narrow. This 

 observation led the nurserymen and the experiment stations in the 

 countries mostly interested, to try to obtain, by hybridizing, new 

 varieties having a wider range of adaptation. This has been done with 

 two different objects in view. Some simply crossed the American 

 resistant varieties to obtain new grafting stocks having a larger range 

 of adaptation; we will call these Americo X American hybrids. Others 

 tried to cross the American resistant stocks with the Vinifera-producing 

 varieties, to obtain a resistant direct producer; we will call these 

 Vinifera X Americans. So far the latter have only succeeded in making 

 some good grafting stocks, the bearing qualities of the Vinifera not 

 being transmitted. 



AMERIGO X AMERICAN HYBRIDS. 



Mr. Munson, in the United States, and a great number of scientists in 

 Europe (Couderc, Millardet, Grasset, Foex, Ravaz) have created a 

 large number of new hybrids, some of the most promising of which we 

 will review. 



Riparia X Rupestris. This group is probably one of the most inter- 

 esting. Among the varieties selected as the best at present we find 

 NOB. 3306 and 3309 of Couderc and No. 101 U of Millardet. They are 

 very resistant to phylloxera, root easily from cuttings, and give a high 

 percentage of good grafts. The trunk increases rapidly in size, so that 

 there is little difference between stock and scion; the fructification after 

 grafting is good and regular. The range of adaptation is a combination 



