CEPAGES. 



127 



Fig. 62. Upper face of a vine leaf, showing the opening Fig. 63. Side view, showing 

 of phylloxera galls. phylloxera galls. 



rated artificially, by placing in the ground every year roots 

 or leaves (with galls*) covered with insects (Figs. 62 and 63). 

 It is also necessary to plant at the same time rootlings 

 of Rupestris, Riparia, Vialla, Solonis, Jacquez, York, etc., 

 the resistance of which is known. This study must be 

 carried out both in the open field and in artificial soils in 

 pots. A comparative examination of the roots of the new 

 cepages and those of the check known varieties enables an 

 opinion to be formed on their resistance to phylloxera after 

 a very short period. Only, before drawing definite conclu- 

 sions, we must remember that many non-resistant vines have 

 less nodosities on their hair roots than resistant vines. 

 Every year the nodosities and tuberosities (Figs. 64, 65, 66, 

 67, 68) of the roots of the young seedlings must be examined, 

 to ascertain if they offer a sufficient guarantee of resistance. 

 It is better, although not indispensable, to plant them in 

 relatively dry soil, so that the action of the soil in no way 

 interferes with that of the phylloxera. If, during several 

 years, we notice that the roots have no tuberosities, but only 

 nodosities, in presence of phylloxera, the resistance is almost 

 certainly assured. It is certainly better to notice a few 

 nodosities on the roots than no lesion at all, for this would 

 prove that the insect had not been able to develop in the 



