involving the epidermis, so that this portion of the sporophyll-base may be described as consisting of a mass of mucilage bounded below by a structureless membrane[112].” Dehiscence of the sporangia occurs at the middle of the distal face (fig. 127, _x_). As seen in the radial section (fig. 127, _ma_) the outer margin of the base of the sporophyll bears a short outgrowth. The leaf-bases of each whorl hang down between the sporangia of the alternating whorl below, and the base of each sporophyll is coherent with the margins of the two sporophylls of the next lower whorl between which it lies, the sporangia being thus closely packed and lying in a pocket “open only on the outer surface of the cone.” Fig. 128 represents a transverse section through a cone in the plane AA of fig. 127; this traverses the sporangia and their subtending bracts (_b_) of one whorl and the dependent bases of the sporophylls of the next higher whorl in the region of the mucilage-sacs (_m_), which are bounded at the periphery by the outer tissue of the sporophylls (_a_). A transverse section in the plane BB of fig. 127 is shown in fig. 129: the pedicels and a part of each vascular strand are seen at _b_ radiating from the axis of the cone; one sporophyll (_sp, a_) is cut through in the region of the pad of tracheal tissue that characterises the short sporangial stalks. The upper portions of the sporangia of the next lower whorl, which project upwards against the mucilaginous bases of the sporophylls above (cf. fig. 127, BB) are shown at _c_ and external to them, at _a_, the section has cut through the outer persistent portions of these sporophyll bases. [Illustration: FIG. 127. Radial longitudinal section of the cone of _Lycopodium cernuum_. (After Lang.)] [Illustration: FIG. 128. Transverse section of the cone of _Lycopodium cernuum_, in its plane AA of fig. 127. (After Lang.)] [Illustration: FIG. 129. Transverse section of the cone of _Lycopodium cernuum_ in the plane BB of fig. 127. (After Lang.)] As Lang points out, this highly complex structure is an expression of the complete protection afforded to the sporangia of a plant met with in exposed situations in the tropics; it is also of importance from a morphological standpoint as exhibiting an agreement with the extinct type of Lycopod cone represented by _Spencerites_. =Selaginellaceae.=