Needless to say, this is quite different from the gradual transformation of species that Darwinism or Lamarckism assumes to take place. One species becomes another _per saltum_ in virtue of some special energy infused into it, some original tendency of its intrinsic nature, not because of gradual modification by forces outside of the organisms, nor because of the combination of influences they are subjected to from without and within, because of tendency to evolute plus {218} environmental forces. This throws biology back to the permanency of species in themselves, though successive generations may be of different species, and does away with the idea of missing links, since there are no gradual connecting gradations. A very interesting phase of Mendel's discoveries is concerned with the relative value of the egg-cell and the pollen-cell, as regards their effect upon future generations. It is an old and oft-discussed problem as to which of these germinal particles is the more important in its influence upon the transmission of parental qualities. Mendel's observations would seem to decide definitely that, in plants and, by implication, in animals, since the germinal process is biogenetically similar, the value of both germinal particles is exactly equal. In a note, Mendel says:-- _In pisum_ (i. e. in peas), it is beyond doubt that, for the formation of the new embryo, a perfect union of the elements of both fertilizing cells must take place. How could we otherwise explain that, among the offspring of the hybrids, both original types reappear in equal numbers, and with all their peculiarities? If the influence of the egg-cell upon the pollen-cell were only external, if it fulfilled the role of a nurse only, then the result of each artificial fertilization could be no other than that the developed hybrid should exactly resemble the pollen parent, or, at any rate, do so very closely. These experiments, so far, have in no wise been confirmed. An evident proof of the complete union of the contents of both cells is afforded by the {219} experience gained on all sides, that it is immaterial as regards the form of the hybrid which of the original species is the seed cell, or which the pollen parent! This is the first actual demonstration of the equivalent value of both germinal particles as regards their influence on transmission inheritance in future generations. It is only by simplifying the problem so that all disturbing factors could be eliminated that Mendel succeeded in making this demonstration. Too many qualities have hitherto been considered with consequent confusion as to the results obtained. It is of the genius of the man that he should have been able to succeed in seeing the problem in simple terms while it is apparently so complex, and thus obtain results that are as far-reaching as the problem they solve is basic in its character. Bateson, in his work Mendel's _Principles of Heredity_, says:--