BRTOPHYTA. 216 



same " flower," but in other cases they occur upon differ- 

 ent parts of the same plant (monoecious) or even upon 

 different plants (dioecious). ' 



396. The act of fertilization requires water; but as the 

 antherozoids are very minute, a dewdrop may be sufficient. 

 The antherozoids swim to the open neck of the archegone, 

 down which they pass to the germ-cell. The germ-cell 

 now begins to divide rapidly, growing upward and eventu- 

 ally forming the spore-fruit. In most mosses the spore- 

 fruit is narrow and elongated below, forming a stalk which 

 supports its upper spore-bearing part (the capsule or spore- 

 case). 



397. The spore-case, when ripe, usually opens by a lid 

 which falls off, leaving a round opening, generally fringed 

 with many teeth (Fig. 136, G and H). In most species 

 as the spore-fruit elongates it carries up the remains of the 

 distended archegone as a little cap (calyptra) (Fig. 136, 

 E,c). 



398. The spores, which are round or angular cells con- 

 taining protoplasm, chlorophyll-granules, oil-drops, etc., 

 germinate quickly upon moist soil. Each spore protrudes 

 a tubular filament, which develops into a conferva-like 

 branching growth of green cells, called the protonema (Pig. 

 137). Upon this buds are eventually produced from which 

 spring up the leafy stems, thus completing the round 

 of life. 



399. There are four orders of Mosses, including about 

 4500 species, as follows: (1) Order 34, AwDREiEACETB, 

 composed of a lew small and rare mosses. (3) The Peat- 

 mosses (Order 35, Sphagnacb^), composed of large, soft, 

 and usually pale-colored plants, with clustered lateral 

 branches; they inhabit bogs and swampy places, where 



