These references will suffice to show that Darwin is in full accord with the main argument of Lamarck. In fact, the curious hypothesis of pangenesis that Darwin advanced was invented partly to account for the inheritance of acquired characters. Despite the hesitancy that Darwin himself felt in advancing this view, and contrary to Huxley’s advice, he at last published his provisional hypothesis of pangenesis in the twenty-seventh chapter of his “Animals and Plants under Domestication.”
The study of bud variation, of the various forms of inheritance, and of reproduction and of the causes of variation, led him, Darwin says, to the belief that these subjects stand in some sort of relation to each other. He says: “I have been led, or rather forced, to form a view which to a certain extent connects these facts by a tangible method. Every one would wish to explain to himself, even in an imperfect manner, how it is possible for a character possessed by some remote ancestor suddenly to reappear in the offspring; how the effects of increased or decreased use of a limb can be transmitted to the child; how the male sexual element can act not solely on the ovules, but occasionally on the mother form; how a hybrid can be produced by the union of the cellular tissue of two plants independently of the organs of generation; how a limb can be reproduced on the exact line of amputation, with neither too much nor too little added; how the same organism may be produced by such widely different processes, as budding and true seminal generation; and, lastly, how of two allied forms, one passes in the course of its development through the most complex metamorphoses, and the other does not do so, though when mature both are alike in every detail of structure. I am aware that my view is merely a provisional hypothesis or speculation; but, until a better one be advanced, it will serve to bring together a multitude of facts which are at present left disconnected by any efficient cause.”
In presenting the hypothesis of pangenesis Darwin begins by enumerating the different kinds of sexual and asexual processes of reproduction, for which he hopes to offer a provisional explanation. Here we find mentioned various methods of budding and self-division, regeneration, parthenogenesis, sexual reproduction, and the inheritance of acquired characters. It is with the last only that we are here chiefly concerned; in fact, the need of an hypothesis _of this sort_ to explain the other kinds of inheritance is by no means evident. There are, however, two other phenomena, besides that of the supposed inheritance of acquired characters, to which the hypothesis of pangenesis might appear to apply specially, namely, the effect of foreign pollen on the tissues of the mother plant, and the supposed influence of the union with the first male on the subsequent young (telegony). It is, however, far from being shown that any influence of this latter kind really occurs, despite the fact that it is generally believed in by breeders.