50 AMERICAN VINES. 



varieties of V. Labrusca may be due, in this case, to the 

 superficial layer of soil being only slightly calcareous and to 

 the layering developing surface roots, which, for a certain 

 time at least, live in that superficial layer, and also to the 

 young roots replacing those destroyed by the phylloxera. In 

 slightly calcareous, compact and rich soils, these varieties 

 are grafted on Taylor. We shall see that its properties of 

 adaptation and resistance are transmitted to its hybrids 

 which are, therefore, very sensitive to chlorosis and phyl- 

 loxera. 



The V. Labrusca is, therefore, of no value for re constitution 

 of European vineyards. It roots freely from cuttings, as 

 applies to all the species from the north of America, and 

 the graft knits well with European vines; it resists attacks 

 of oidium and mildew well, but its fruit is very sensitive to 

 black rot, and its roots to pourridie. 



V. CALIFORNICA. 



(a) Description. Stump very vigorous, trunk very strong; 

 habit, creeping; wood of the year deep greyish -brown, ten- 

 drils discontinuous. Leaves (Fig. 9) large, entire, obicular, 

 as wide as long; petiolar sinus widely open; limb, thin, 

 bright green on the upper-face, whitish -green tomentose on 

 under-face; teeth acute, in two series. Bunch long, small; 

 berries small, spherical, of a deep violet black colour, clean 

 taste. Seeds (Fig. i o) small, distended; beak blunt; chalaze 

 oval, terminating level with the position of the raphe (which 

 is absent). Roots rather large. 



(b) Varieties. The variations in form of V. Californica 

 are excessively numerous ; certain varieties have very marked 

 characters, such as those growing in the dry sands of the 

 south of California, which T. V. Munson regarded as a 

 species and named V. Girdiana. These forms often have 

 lobed leaves, without teeth, and thick, short , stiff hair on the 

 under-face. We also meet with variations differing from the 

 main type in other ways, such are the forms with very large, 

 thin, entire leaves, with acute teeth, very slightly tomentose; 

 these are the most vigorous, forms. These morphological 

 variations are almost always dependent on the fertility of 

 the soil, but as they do not present any interest for the re- 

 constitution of our vineyards it is of no advantage to discuss 

 them. 



