MUSCI, 



3^9 



trichum Lyelli and ohtusifolium ; in O. phyllanthum tufts of club-shaped protonemal 

 filaments with short cells arise at the apex of the leaves ; and the same phenomenon 

 occurs in Grimmia trichophylla^ Syrrhopodon, and Calymperes. In Oncophorus 

 glaucus a dense felt of interlacing protonema-filaments is formed at the summit 

 of the plant where the reproductive organs are produced, which arrests its further 

 growth, and hence produces at a later period new clumps of young plants. In 

 Buxbaumta, especially B. aphylla, the marginal cells of the leaves form a pro- 

 tonema enveloping them as well as the stem with its filaments. Lastly, even 



Fig. z^i.—Tetraphis pellucida ; A a plant producing gem- 

 ma (natural size) ; B the same, magnified ; y the cup in which 

 the gemmae are collected ; C longitudinal section through the 

 summit of the plant, b the leaves of the cup, K the gemmae in 

 various stages of development ; the older ones are forced off 

 their stalks by the later growth of the younger ones, and forced 

 over the side of the cup ; D a mature gemma (X 500), consisting 

 at the margin of one, in the centre of several layers of cells. 



Fig. 252. — Tetraphis pelhicida; A, b a. gemma, detached 

 from its stalk at a, the protonema-filament *• >» has been formed 

 by the growth of a marginal cell of the gemma, and the flat 

 structure / as a lateral outgrowth from the protonema ; this has 

 also put out root-hairs w, w', w'' (X 100) ; B,p a flat protonema 

 from the base of which a leaf-bud K and root-hairs w, w' have 

 sprung ; the base of the protonema often puts out a number of 

 new flat protonemata before a leaf-bud is formed. 



detached leaves, if kept moist, may emit a protonema, as for instance those of 

 Funaria hygrometrica ^. 



GemmcB^ which, like those of the Marchantiese, are stalked fusiform or lenti- 

 cular cellular bodies, occur in Aulacomnion androgynum at the summit of a leafless 

 elongation of the leafy stem [Pseudopodtum) ; in Tetraphis pellucida enveloped by an 

 elegant cup composed of several leaves, out of which they subsequently fall. These 



^ [It has been shown by Pringsheim (Jahrb. fur, wiss. Bot. XI) and by Stahl (Bot, Zeit. 1876) 

 that the sterile cells of the sporogonium and of the seta may give rise to protonema.] 



B b 



