164 CRYPTOGAMOUS OR FLOWERLESS PLANTS. [SECTION 17. 



end of the stem. The analogue of the anther (Antheridium) is a cellular 

 sac, which in bursting discharges innumerable delicate cells floating in a 

 mucilaginous liquid; each of these bursts and sets free a vibratile self- 

 531 534 541 540 



moving thread. These threads, one or more, reach the orifice of the pistil- 

 shaped body, the Pistillidium, and act upon a particular cell at its base 

 within. This cell in its growth develops into the spore-case and its stalk 

 (when there is any), carrying on its summit the wall of the pistillidium, 

 which becomes the calyptra. 



501. Liverworts or Hepatic Mosses {Hepatica) in some kinds re- 

 semble true Mosses, having distinct stem and leaves, although their leaves 

 occasionally run together ; while in others there is no distinction of stem 

 and leaf, but the whole plant is a leaf-like body, which produces rootlets on 

 the lower face and its fructification on the upper. Those of the moss-like 

 kind (sometimes called Scale-Mosses) have their tender spore-cases splitting 

 into four valves ; and with their spores are intermixed some slender spiral 



Fig. 529. Mnium cuspidatum, smaller than nature. 530. Its calyptra, detached, 

 enlarged. 531. Its spore-case, with top of stalk, magnified, the lid (532) being 

 detached, the outer peristome appears. 533. Part of a cellular ring (annulus) 

 which was under the lid, outside of the peristome, more magnified. 534. Some 

 of the outer and of the inner peristome (consisting of jointed teeth) much magni- 

 fied. 535. Antheridia and a pistillidium (the so-called flower) at end of a stem 

 of same plant, the leaves torn away (cf, antheridia, $. pistillidium), magnified. 

 536. A bursting antheridium, and some of the accompanying jointed threads, 

 highly magnified. 537. Summit of an open spore-case of a Moss, which has 

 a peristome of 16 pairs of teeth. 538. The double peristome of a Hypnum. 

 539-541. Spore-case, detached calyptra, and top of more enlarged spore-cast> 

 and detached lid, of Physcomitrium pyriforme (Fig. 527) : orifice shows that there 

 is no peristome. 



