If the disk is cut entirely from the stalk and placed on moist sand, it produces adventitious buds in the region at which the stalk was removed. Buds are also produced at the bases of the rays that go off from the disk. They arise from the under side of the rays without regard to the position of the disk, _i.e._ whether it is turned upward or downward. If the rays are cut off they produce new buds at the base (Fig. 9, _F_), and if the outer tip of the ray is also cut off, the new bud still arises at the base, as shown in Fig. 9, _F¹_. These results on pieces with limited growth agree in every respect with those that have been obtained in flowering plants. Vöchting thinks that the phenomenon is due in all cases to the limited growth of the parts. Goebel rejects this interpretation, and thinks that the results can be accounted for by the direction of the movement of formative or, at least, of building material. In favor of this view, he points out that in other liverworts the polarity is not shown in the same degree as in lunularia (according to Schostakowitsch), and also that in very old pieces of marchantia, as Vöchting has shown, the polarity disappears. In the latter case the attractive action at the vegetative point, to which the building stuff is supposed to flow, is less strong; and in longer pieces the influence of the apical region may not extend throughout the entire length of the thallus. In favor of this interpretation he points out that in young prothallia of osmunda, adventitious shoots do not appear, but in older plants, that have become longer, these shoots may appear at the base, because this region is no longer influenced by the apex, and consequently it is possible for building material to accumulate at the basal end. It may be granted that Goebel’s idea is possibly correct, viz. that the apex, or the apical end of a piece, may have some influence in preventing the development of shoots at the base, but it does not follow that this influence can be accounted for on the ground of a withdrawal of building stuff from the basal part. As I shall attempt to show in a later chapter, this influence may be of a different nature. It has been found by Pringsheim and others that pieces of the stem of mosses may also produce new plants, and this holds even for pieces of the stalk of the sporophore and of the wall of the spore capsule (Fig. 10, _A-D_). In this case, however, there is not produced a new moss plant directly from the end of the piece, but threads or protonemata grow out, as shown in Fig. 10, _A, B_, and from these new moss plants are formed in the same way as on the ordinary protonema. The threads that arise from the piece grow out from single cells in the middle part of the stem. These cells are less differentiated and are richer in protoplasm than are the other cells in the stem.