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PHYTOGENESIS. 259 for instance, does not always take place in such a manner that the parent plant separates itself entirely from them, and scatters them about singly, but it most frequently forms, previous to its own individual death, a peculiar organ, which places the offspring in a peculiar vital connexion with one another, and at the same time serves as a reservoir for a certain quantity of nutritive material, by which the first development of these young individuals is facilitated. But in most cases this organ is merely a metamorphosis of some other one with which we are already familiar, for example, the stem or the root, or, as in the potato, the axillary buds; and no scientific person has therefore ever hesitated to speak of these things as mere portions of a plant, which continue to live as connecting members between the younger individuals after the death of that one which has generated them. On the other hand, a different course has been taken, where stem and root simultaneously, and therefore almost the entire totality of the plant, take part in the formation; and although the result in this case may perhaps be that there can be no question at all of an heteromorphy of a known portion of a plant, still the physiological identity in the signification of this and the former part has not been maintained with precision, and the view has thus been obscured.

Most manuals are silent upon this subject, as though it were quite self-evident that the tree was to be regarded as the perfect plant; and I believe it not difficult to prove that, where vegetable physiology still lies very deep in error, this particular misconception is solely in fault. Two entirely distinct ideas have here been confounded, namely, the highest stage of development to which vegetable life can raise itself, and the type upon which the idea of the individual must be based. If, then, the first of these ideas may be maintained with regard to the tree, still the application of the second to it fails completely in every respect, as has been very correctly asserted before by E. Meyer (Linnea, vii, p. 424). It necessarily pertains to the notion of a plant, that it produces foliaceous organs on its stem, yet there is no tree which has leaves. Paradoxical as this may sound, it is still not the less true. It is a fact, of which certainly no botanist is ignorant, that no lignified part of a plant, even though it be only in its second year, is capable