17 



form type proves this. It has probably originated through the 

 blending of Riparia with one or more southern species, possibly 

 the Monticola and Cordifolia, but taking after the first-named 

 entirely in growth habit. By a peculiar Combination of the quali- 

 ties of its parents it is enabled, although an exceedingly free 

 grower, to exist in a hot country. We know from our California 

 experience- that such deep and poor gravelly soils with, perpetual 

 moisture in their lower strata, on which it is found wild, are not 

 exceedingly favorable {or the Anaheim diseases. 



It must strike us as peculiar that there are no intermediate 

 forms in regard to growth habit, excepting possibly some scattered 

 individual vines here and there, between Riparia and Labrusca 

 on one side and species occurring in the southern States (sluggish 

 growers) on the other side. Vinifera has the intermediate forms, 

 but these could not occur in intermediate regions on account of 

 the Phylloxera, Anaheim and other diseases. The phenomenon 

 is easily explainable by the climatic conditions of the East. The 

 change from the frost belt to the almost frostless belt is very 

 abrupt. 



All American species, excepting the Californica and possibly 

 the Arizonica have developed by natural selection under the in- 

 fluence of the Anaheim disease in their respective areas and soils. 

 They are threfore all, with the one expectipn, perfectly hardy against 

 it in their own locality, but generally not perfectly hardy anywhere 

 else. The Californica very, likely has descended from a species 

 highly resistant to the Phylloxera, but as it came to California and 

 attained its present character, before the insect found its way here 

 through the agency of man, mpst of its resistance has been lost. 

 Resistance to the Phylloxera is not an original or generic quality 

 wth the grape vine. If it was, all vines would have about the 

 same resistance. A vine can not develop any of it without the 

 actual presence of the insect on its roots, but it may be there by 

 inheritance. 



The Californica, with one .other possible one, Labrusca, 

 comes nearer having about the average growth habit of the Vini- 

 fras, than any other American species. After having been absent 

 in numerous transitional forms, the original growth habit of the 

 grape vine appears again, as the Californica developed with only 

 climate and soil exerting their influence and without the influence 

 of the Anaheim disease. It is not probable, that it has descended 

 directly from the Labrusca, as this species could not overleap the 



