328 



MUSCINEM. 



penetrated with water to their very summits like a sponge, even when their tufts stand 

 high above the surface of the water. 



The Archegonia and Antheridia of Sphagnum arise on the fascicled branches, as 

 long as they are still near the summit of the primary stem and belong to the terminal 

 tuft. The time of flowering is mostly in autumn and winter, but is not exclusively 

 confined to these periods. The antheridia and archegonia are always distributed on 

 different branches, sometimes even on different plants, and in this case the male and 

 female plants- form large distinct patches. When the primary stem does -not con- 

 tinue to grow during the development of the sporogonia in dry weather, growth still 

 takes place subsequently at the terminal tuft ; but when the supply of water is great 

 and vigorous increase of length takes place, the fertile branches diverge from one another, 

 and are consequently found lower down on the stem ; and the sporogonia and older male 

 inflorescences are thus removed to a distance from the summit, although at the time of 

 flowering they stand near it. The branches which bear the antheridia are generally 



Fig. 240. — Sphagnum aatti/olium ; A a portion of the surface o 

 the leaf seen from above, cl the tubular cells containing chlorophyll, 

 y the spiral bands, / the holes in the large empty cells ; B transverse 

 section of a leaf, cl the cells that contain chlorophyll, Is the large empty 

 cells. 





Fig. 241. — Sphao-7iii7n acHtifoliinn; A a male 

 branch, with the leaves partially removed in order 

 to show the antheridia a; .6 an open antheridium 

 (verj' strongly magnified) ; C a free motile an- 

 therozoid (after Schimper). 



conspicuous externally by their imbricated leaves forming beautiful densely crowded 

 orthostichies or spiral parastichies ; the leaves are generally yellow, bright red, or 

 especially dark green, and can hence be easily recognised (Fig. 239, « a). The an- 

 theridia stand, on the mature shoot, by the side of the leaves ; they are never terminal, 

 and are found only in the middle part of the male branch, one standing beside each 

 leaf ; the male branch may therefore continue to grow at the summit, and become 

 an ordinary flagellate branch. This position of the antheridia, and still more their 

 roundish form and long pedicel, causes the Sphagnaceae to resemble some Junger- 

 mannieae ; the mode in which they open (Fig. 241) recalls the Hepaticse even more 

 than the true Mosses. The archegonia arise at the blunt end of the female branch, 

 the upper leaves of which form a bud-like envelope ; but the young perichaetial leaves 

 are still contained within this at the time of fertilisation, although they afterwards 

 become further developed. The archegonia are exactly like those of the rest of the 



