_Reproductive Shoots[103]._ In _Lycopodium Selago_ the foliage leaves serve also as sporophylls and, as Professor Bower[104] has pointed out, the branches exhibit to some extent a zonal alternation of sterile and fertile leaves; in other species, in which foliage leaves and sporophylls are practically identical, the sporangia occur sporadically on the ordinary leaves. In species with well-defined terminal cones the lower sporophylls may bear arrested sporangia and thus form transitional stages between sterile and fertile leaves, a feature which occurs also in the male and female flowers of many recent Araucarieae[105]. The sporangia[106] (fig. 126, D, F) are usually reniform and compressed in a direction parallel to the surface of the cone-scales; they are developed from the upper surface and close to the base of the fertile leaf to which they are attached by a short and thick stalk (_e.g._ _L. inundatum_) or by a longer and more slender pedicel (_L. Phlegmaria_, fig. 126, E). On maturity the sporangia open as two valves in the plane of compression and the line of dehiscence is determined in some species at least by the occurrence of smaller cells in the wall. In transverse sections of cones in which the sporangia are strongly saddle-shaped, the sporophylls may appear to bear two sporangia. This is well shown in the section of a cone of _L. clavatum_ shown in fig. 126, F. The sporangia _a_ and _b_ are cut through in an approximately median plane showing the irregular outline of the sterile pad (_p_) of tissue in the sporogenous cavity. Those at _c_ and _d_ have been traversed at a lower level and the two lobes of the saddle-shaped sporangia are cut below the attachment to the sporophyll. The distal laminae of the sporophylls, cut at different levels, are seen at the periphery of the cone. [Illustration: FIG. 126. A. _Lycopodium cernuum_, longitudinal section of strobilus; _a_, band of lignified cells. B. _L. cernuum._ Cell from sporangium wall. C. _L. cernuum._ Sporophyll and sporangium; _lt_, vascular bundle. D. _L. clavatum._ Part of radial longitudinal section of strobilus; _p_, sterile tissue. E. _L. Phlegmaria._ Sporophyll and stalked sporangium. F. _L. clavatum._ Transverse section of strobilus; _p_, sterile pad.]