Organography of plants, especially of the archegoniatae and spermaphyta . eudo-triquetrum (?). Separation-cells which havecolourless contents and whose walls swell up are formed by intercalarydivisions. The remaining portions of the pro-embryo which contain chloro- * Goebel, Uber die Jugendformen von Pflanzen und dercn kiinstliche \Viederhervomifiuig, inSitzungsberichte der bayerischen Akademie, 1896. 126 GERMINATION OF THE SPORE IN MUSCI phyll may then grow out into new protonema. This division of the proto-nema into single cells, or it may be into cell-masses, is the most primitivemethod of
Organography of plants, especially of the archegoniatae and spermaphyta . eudo-triquetrum (?). Separation-cells which havecolourless contents and whose walls swell up are formed by intercalarydivisions. The remaining portions of the pro-embryo which contain chloro- * Goebel, Uber die Jugendformen von Pflanzen und dercn kiinstliche \Viederhervomifiuig, inSitzungsberichte der bayerischen Akademie, 1896. 126 GERMINATION OF THE SPORE IN MUSCI phyll may then grow out into new protonema. This division of the proto-nema into single cells, or it may be into cell-masses, is the most primitivemethod of the formation of gemmae, and it happens especially when theexternal conditions for vegetative growth are unfavourable. Schistostega. In Schistostega ^ the end of the filament, composed ofa row of cells, separates off in quite the same way by a separation-cell, butthere is evidently here a little more specialization of the gemma as such. Ephemeropsis. The formation of an anchor at the base of the gemmaof Ephemeropsis is remarkable; the gemma after its separation can fix. Fig. 105. Buxbaumia indusiata. i, protonema-thread bearing a male plant; If, rhizoid. 2, protonema-thread with two male plants, one seen from in front, the other from behind. 3, young male plant on a proto-nema-thread. 4, half-diagrammatic longitudinal section of a male plant. 5, 6, cell-grouping in young and 2, magnified 200. 3, more highly magnified. itself firmly, by means of the projecting arm of its anchor, to the surface ofthe leaf if this should ofter a slightly rough surface. The gemmae of the protonema of many other Musci are cell-bodieswhich are adapted to a period of rest and possess thickened, often brown,outer walls. To describe these structures here would carry me too far. Inmany cases, although not in all, they are arrested stages of buds of moss-plants. Investigation is required to show whether they do not play fre- Noll, Uber das Leuchten der Schizostega osmundacea, in Arbeiten aus dem
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