i68 THE POPULAR SCIENCE MONTHLY. 



cause of their failure. Take as an instance the case of the Catawba. 

 It is in growing demand in the Mississippi Valley, as, so far, the best 

 white-wine grape, and the only one extensively used in the manu- 

 facture of sparkling wines. Yet it is, in this part of the country, one 

 of the most susceptible to the Phylloxera disease, and its successful 

 growth becomes more and more uncertain. If by a thorough under- 

 standing of the disease, and by the system of grafting which I have 

 suggested, this vine can be successfully grown in the Mississippi 

 Valley, it is safe to say that the value of our vineyards will be 

 doubled ; as the Concord, which is now the main reliance, and which 

 makes but an inferior wine, has already so glutted our markets as" 

 scarcely to pay the grower. 



Why the Insect is more injurious in Europe than in America. 

 — Without going into particulars, several good reasons may be given 

 to explain the fact that Phylloxera is more devastating in the vine- 

 yards of France than in our own. There exists a certain harmony 

 between the indigenous fauna and flora of a country, and our native 

 vines are such as from their inherent peculiarities have best withstood 

 the attacks of the insect. The European vine, on the contrary, 

 succumbs more readily, not only because of its more tender and 

 delicate nature, but because it has not been accustomed to the disease 

 — there being, doubtless, a parallel between this case and the well- 

 known fact that diseases and parasites which are comparatively 

 harmless among peoples long accustomed to them, become virulent 

 and often fatal when first introduced among hitherto uncontaminated 

 peoples. 



Then the particular natural enemies of the insect which belong to 

 its own class, and which in this country help to keep it within due 

 bounds, are lacking in Europe ; and it will require some time before 

 the closely allied European predaceous species will prey upon and 

 check it there to the same extent. 



The Phylloxera will, also, other things being equal, have an advan- 

 tage in those countries where the mildness and shortness of the winter 

 allow an increase in the annual number of its generations. Finally, 

 the difi*erences in soil and in modes of culture have no insignificant 

 bearing on the question in hand. Though Phylloxera, in both types, 

 is found on our wild vines, it is very doubtful if such wild vines, in a 

 state of nature, are ever killed by it. With their far-reaching arms 

 embracing shrub and tree, their climbing habit unchecked by the 

 pruner's knife; these vines have a corresponding length and depth of 

 root, which render them less susceptible to injury from an under- 

 ground enemy. Our own method of growing on trellis approaches 

 more nearly these natural conditions than that employed in the 

 ravaged French districts, where the vines are grown in greater prox- 

 imity and allowed to trail on the ground, or are supported by a single 

 stake. 



