. The Bible and science. FiG. 24.—Part of fern-leaf, bearing clusters of spore-cases. tiated into cells of the root, of the stem, and of theleaves. In mosses they are differentiated in this manner—roots, stem, and leaves being all different, but stillthey are composed only of cells. In ferns we have some of the cells uniting so asto form vessels, but still we have no such differentia-tion of the reproductive apparatus as in the exogensand endogens. In lycopods or club mosses, those trailing plantswhich we see so commonly on Highland moors, there G 82 PEOTHALLIUM IN LYCOPODS. is tlie same alter
. The Bible and science. FiG. 24.—Part of fern-leaf, bearing clusters of spore-cases. tiated into cells of the root, of the stem, and of theleaves. In mosses they are differentiated in this manner—roots, stem, and leaves being all different, but stillthey are composed only of cells. In ferns we have some of the cells uniting so asto form vessels, but still we have no such differentia-tion of the reproductive apparatus as in the exogensand endogens. In lycopods or club mosses, those trailing plantswhich we see so commonly on Highland moors, there G 82 PEOTHALLIUM IN LYCOPODS. is tlie same alternation of generations as in mossesand ferns, the spore produces a prothallium, but withthis difference, that the prothallium remains withinthe spore and does not grow as a large cellular plant. i^«= \ ^^. Fig. 25.—Lycopod. from it, as in mosses and ferns. It has, as it were, sfota start of the mosses and ferns, for their spore has todevelop into a cellular expansion, which has to growon the ground for some time before it can produce GYMNOSPERMS. 83 sexual organs from which a plant like the former isto come. But the spore of the lycopod develops itscellular expansion bearing reproductive organs withinitself, so that when it falls on the ground the newplant is ready to grow up like its parent. The lycopods also differ from the mosses and fernsin the formation of the spermatozoids, for these are
Size: 1113px × 2246px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectnaturalhistory, booky
