. Studies in fossil botany . Paleobotany. io6 STUDIES IN FOSSIL BOTANY towards the axis, the epidermal cells are much enlarged, and these large cells of the pedicel are continuous with those that form the wall of the sporangium itself (Figs. 43 and 44). To- wards the free end of the sporangium, the cells of the wall become much smaller, and it was prob- ably at this end that dehiscence took place, the large cells perhaps performing the functions of an annulus. These cells were strengthened by buttresses projecting from their lateral cell- walls, much as in the sporangium of Cala- mostachys. Th
. Studies in fossil botany . Paleobotany. io6 STUDIES IN FOSSIL BOTANY towards the axis, the epidermal cells are much enlarged, and these large cells of the pedicel are continuous with those that form the wall of the sporangium itself (Figs. 43 and 44). To- wards the free end of the sporangium, the cells of the wall become much smaller, and it was prob- ably at this end that dehiscence took place, the large cells perhaps performing the functions of an annulus. These cells were strengthened by buttresses projecting from their lateral cell- walls, much as in the sporangium of Cala- mostachys. The spor- angium is seated, with a broad base, on the recurved end of the pedicel ; the sporangial Fig. 44.âSpheiiophyllum Damsom. Sporangio- *â ° phore and its sporangium, shown in trans- wall in this region is verse section above, and in longitudinal section (somewhat oblique) below, sp, spor- lined by a delicate tissue angiophore ; sm, sporangium, containing \ spores. X 45. Phil. Trans., W. and S. \PX%- 44> Will. Coll. .8,8, H. and E. The spQres wer£ numerous in each sporangium; and so far as at present observed, were all of one kind, though rather variable in size. Their average diameter is about .09 mm. The spore-membrane shows a characteristic sculpturing, consisting essentially of prominent spines, connected. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Scott, Dukinfield Henry, 1854-1934. London, A. and C. Black
Size: 1172px × 2132px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublisherlondonaandcblack
