the result shows the influence of the major component on the small piece, causing it to produce a head and not a tail at its aboral end, but I think that this conclusion would be erroneous, because it seems much more probable that we have here a case of heteromorphosis, similar to that in _Planaria lugubris_, and that the result depends entirely on the action of the smaller component. It is hardly possible to demonstrate that this is the correct interpretation, since if a small piece of this size is isolated it dies before it regenerates. The result is paralleled, however, by the regeneration of a tail at the anterior surface of a posterior piece. The process of grafting has long been practised with plants, but the experiments were made more for practical purposes than to study the theoretical problems involved. Vöchting has, however, carried out a large number of well-planned experiments. He finds that a stem can be grafted upon a root, and a root upon a stem, a leaf upon a stem or upon a root. Even an entire plant can be grafted upon another. The results show, however, in general, that, whatever the new position may be, the graft retains its morphological characters--a shoot remains a shoot, a root is always a root, and a leaf a leaf. Vöchting concludes that there is in the plant no principle or organization that conditions an unchangeable arrangement of the main organs. “The inherited order of the parts, acquired apparently on physiological grounds, may be altered by the experimentator; it is possible for him to change the position of the building blocks within a wide range without endangering the life of the whole.” “It is essential, however, for the success of the experiment that the grafted parts, or tissues, retain their normal orientation. If this condition is not fulfilled there may take place, it is true, a union of the parts, but sooner or later disturbances set in.” Vöchting transplanted pieces in abnormal positions, sometimes reversing the long axis of the grafted piece, sometimes the radial axes, and sometimes both together. In some cases this led to the formation of swellings that interfered with the nourishment but carried with it no further consequences. In other cases the changes went so far that the vital processes were interfered with. At times an incomplete union took place between the parts; at others, even though the first union was perfect, death later ensued.