On the other hand, when similar pieces were grafted with their original orientation, a perfect union took place and the piece became a part of the stock. The results establish, Vöchting claims, that every part and every portion of a part has a polar orientation in one direction, and furthermore, in a body having a radially symmetrical form, there is also a radial polarization; that is, the inner side of each part is different from the outer side of the same surface, even though no such difference is apparent to us. The properties of the tissue-complex rest, in the last analysis, on that of the cells; the properties of the whole being only the sum total of the properties of its elements, so that we may say that every living cell of the root is polarized, not only longitudinally, but also radially; each has a different apical and root pole, a different anterior and posterior pole, and also right and left polar relations. These results, deduced from the experiments in grafting, lead Vöchting to formulate the following rule: “Like poles repel, unlike poles attract.” This rule is the same as the law of the magnet. In fact, Vöchting states that the root and the stem relations show a remarkable resemblance, despite many differences, to a magnet. If the magnet is broken into pieces it may be reunited by bringing unlike poles together, but not by uniting like poles; the same statement holds for the root and the stem. Exception may be taken, I believe, to parts of Vöchting’s conclusions, especially in the light of the recent experiments in grafting in animals. It is by no means to be granted without further demonstration that the properties of the whole organism are only the sum-total of the action of the individual cells. If, as seems to be the case, the cells are organically united into a whole, the properties of this whole may be very different from the sum of the properties of the individual cells, just as the properties of sugar are entirely different from the sum of the properties of carbon, hydrogen, and oxygen.