88 GKAPI-: CULTURE AND 



as a resistant stock for use in its native state, to the climate, 

 of which it must be presumed to be especially adapted. This 

 reasonable presumption gives it so great a claim to attention 

 and renders its preeminent success so probable, that nothing 

 but the strongest proof of its non-resistance should induce us 

 to relinquish its use. Even a cursory examination of its root- 

 habit shows that it understands the climate thoroughly. Two 

 or three strong cord-like roots start a few inches below the 

 surface of the ground, from a short but very stout trunk; and, 

 without branching or emitting rootlets, they go almost directly 

 down for from eight to twelve inches, according to the nature 

 of the soil. Then they begin to branch, but still with down- 

 ward tendency, and without splitting into fine rootlets, until 

 they are fairly below the point to which the summer drought 

 is ordinarily expected to reach. Unlike the Riparia, its roots 

 are thick and fleshy, or cartilaginous, rather than wiry, and 

 one might suppose that it would invite rather than "repel the 

 attacks of the tender-billed insect. The latter attacks it un- 

 hesitatingly, .although it evidently prefers the non-resistant 

 Vinifera roots when these are within reach. The bites of the 

 phylloxera on the cartilaginous roots and rootlets of the 6V///- 

 fornica, however, do not result in the distortion which insures 

 the ultimate death and decay of the organs of the non-resist- 

 ant vines so soon as they begin the process of turning into 

 wood (lignification). The wound will be found surrounded 

 by a raised ring which makes it resemble a miniature crater; 

 but the formation of this swelling does not materially deform 

 the soft root as it would a hard one. As it is well understood 

 that it is not so much the direct depletion caused by the in- 

 sect's feeding, as the death of the roots caused by the distor- 

 tion, that constitutes the fatal injury in the case of the Vinifera 

 stock. The cause of the resistance of the Caiifornica is ob- 

 vious enough. Here and there a rootlet, attacked by over- 

 whelming numbers, may be overcome and die; but if the vine 



