Because the phylloxera aphid destroyed the root system of the ungrafted vinifera vine, it was necessary to graft scions or the fruit-producing part of European vines onto pure American or hybrid Franco-American resistant rootstocks. At first it seemed that the replanting of a vineyard was a simple matter depending on time, labor, and capital. In reality, the reconstitution of the vineyards proved difficult because the rootstocks had to be able to survive in different soils, to be compatible with the varieties of vinifera vines to which they were grafted, and to be capable of giving the desired yield. So vines had to be crossed in various combinations. The crossings were the subject of a great experiment, or rather many experiments, big and small. In view of the time and expense required to complete these risky trials, the use of ungrafted, disease-resistant American vines or direct-production hybrids seemed an easy way out. But the wine from these vines was vastly inferior to that from straight viniferas and French vines grafted on American and hybrid rootstocks.

The grape vine has engaged in an orgy of multiplication of species since it came into existence many millions of years ago.