Now when individuals (bearing contrary characters), pure in the sense indicated, are crossed together, the question arises, What will be the appearance of the first cross individuals? Here again, _generally speaking_, when thoroughly green cotyledons are crossed with thoroughly yellow cotyledons, the first-cross seeds will have yellow cotyledons; when fully round peas are crossed with fully wrinkled the first result will _generally speaking_ be _round_, often with slight pitting as Mendel has stated. This has been the usual experience of Correns, Tschermak, Mendel, and myself[72] and, as we shall see, the amount of clear and substantial evidence to the contrary is still exceedingly small. But as any experienced naturalist would venture to predict, there is no _universal_ rule in the matter. As Professor Weldon himself declares, had there been such a universal rule it would surely have been notorious. He might further have reflected that in Mendel’s day, when hybridisation was not the _terra incognita_ it has since become, the assertion of such universal propositions would have been peculiarly foolish. Mendel does not make it; but Professor Weldon perceiving the inherent improbability of the assertion conceives at once that Mendel _must_ have made it, and if Mendel doesn’t say so in words then he must have implied it. As a matter of fact Mendel never treats dominance as more than an incident in his results, merely using it as a means to an end, and I see no reason to suppose he troubled to consider to what extent the phenomenon is or is not universal--a matter with which he had no concern. [72] The varieties used were _Express_, _Laxton’s Alpha_, _Fillbasket_, _McLean’s Blue Peter_, _Serpette nain blanc_, _British Queen_, _très nain de Bretagne_, Sabre, _mange-tout_ Debarbieux, and a large “grey” sugar-pea, _pois sans parchemin géant à très large cosse_. Not counting the last two, five are round and three are wrinkled. As to cotyledons, six have yellow and four have green. In about 80 crosses I saw no exception to dominance of yellow; but one apparently clear case of dominance of wrinkled and some doubtful ones.