Plant Diseases and Insects. 99 



carbon, sulpho-carbonate of potassium, and the kerosene 

 emulsion) ; and (3) submersion. 



''It was early found in the histor}' of this phylloxera that 

 most of the cultivated varieties of American grape-vines, as 

 also the wild species, resisted, or were little subject to, the 

 attacks of the root form {radicicola^ of the phylloxera, 

 although the leaf gall form {gatlicola), which in point of fact 

 does little if any permanent damage, occurs in greater num- 

 bers on many of our wild and cultivated sorts than on the 

 European grape-vines, which are all derived from the single 

 species, Vitis vifiifera, and which are so exceedingly subject 

 to the attacks of the root form. This fact was first noticed in 

 France by M. Laliman, of Bordeaux, and later by Gaston 

 Bazille, of Montpellier, and was independently proved on a 

 more extended scale by my earlier investigations in the United 

 States. The use of American stocks upon which to cultivate 

 the susceptible European varieties has resulted in an enor- 

 mous trade in certain American seeds and cuttings and now 

 supersedes all other methods against the insect. 



" It was my privilege and pleasure to spend a week in Au- 

 gust, 1889, among the world-renowned Medoc and Sauterne 

 vineyards of the Bordeaux district in France. Here, by vir- 

 tue of the rich alluvial soil and the ease with which the chief 

 vine3'ards can be submerged, the phylloxera has made slower 

 headway, and the opposition to the use of American resistant 

 stocks has been greatest. Yet they have finally vanquished 

 prejudice and are, either from necessity or choice, rapidly 

 coming into general use. When I say choice, I mean that 

 even where the French vines yet do well and the phylloxera 

 is kept in subjection by other means it is found that great 

 vigor of growth and increase in healthfulness and yield of 

 fruit result at once from the use of American stocks. 



"Without going into a lengthy discussion of the subject of 

 wild American species, those of practical importance to the 

 grape-grower are the following : Vitis cestivalis, V. riparia, 

 and V. Labj'usca. 



"The varieties derived from V. cestivalis are of value for 

 their fruit as well as for their resistant qualities, and, being 

 easily propagated from cuttings, they are very often used in 

 France as stocks. The most important varieties are Jacquez, 

 Herbemont, Black July, and Cunningham. 



