Still another example of theorizing is the doctrine of pangenesis. Darwin’s general theory of evolution which dealt so much with heredity, was closely complicated with the difficulty of understanding how one minute reproductive cell could transmit by inheritance all the complicated variety of organs and functions in a highly developed plant or animal. To meet this difficulty he devised the explanation of pangenesis (he doubts about the name, because ‘my wife says it sounds wicked, like pantheism’),[367] that is, the idea that the primitive cell contains a great number of _gemmules_, each transmitting and originating some particular organ with its varied functions. Here again the theory, as Darwin conceived it, did not find general acceptance, though in some respects it surprisingly anticipates the results of the latest modern research. But the interesting thing is to see the ardor with which its inventor worked it out and the elaborate argument with which he carries it through the latter part of the great work on ‘Animals and Plants under Domestication.’ It is difficult, he admits. He does not blame any one for disputing it, or for rejecting it, or even for laughing at it. ‘The hypothesis of Pangenesis, as applied to the several great classes of facts just discussed, no doubt is extremely complex, but so are the facts.’[368] And then he lets his imagination range more widely than usual in contemplating possible deductions and consequences: ‘No other attempt, as far as I am aware, has been made, imperfect as this confessedly is, to connect under one point of view these several grand classes of facts. An organic being is a microcosm—a little universe, formed of a host of self-propagating organisms, inconceivably minute and numerous as the stars in heaven.’[369] Yet here again he introduces the inevitable reservation and in his Autobiographical Sketch he says: ‘Towards the end of the work I give my well-abused hypothesis of Pangenesis. An unverified hypothesis is of little or no value; but if any one should hereafter be led to make observations by which some such hypothesis could be established, I shall have done good service.’[370] It seems sometimes surprising that, with this marked bent towards abstract speculation, which it was so difficult to control, Darwin should have been always so indifferent to philosophical thought on the ultimate questions of the universe. He admits that he knew little of metaphysics and cared little for them. But this again is instructive as to the peculiar balance of his temperament. He liked to speculate, but he would not speculate for a moment without a firm foundation of fact. His feet must be based first on the solid tangible earth. Then if his head would not reach the clouds, he would keep out of them. IV