14 PIGEON-WHEAT MOSS. 



The Z/eaves are green or brownish, and grow mostly 

 from the upper part of the stem. They are (1) long- 

 pointed, and shaped somewhat like a spear or lance, only 

 narrower, approaching the form of a line ; hence 

 they are said to be linear-lanceolate. The edges are serru- 

 late (Lat. serrula, a little saw). 



The Stalfc (b c) rises from the top of the stem among 

 the leaves, and is therefore said to be terminal ; and as it 

 supports the fruit, it is called the pedicel (pediculus, a little 

 foot). It is erect, usually longer than the stem, smooth, 

 brown, thread-shaped (filiform). 



The Fruit (c) is borne aloft on the pedicel. It is the 

 last part produced by the plant, the chief end and aim of 

 its whole life. It is a small square box or capsule (7), 

 covered while growing by a hairy cap or calyptra (6). 

 When ripe, the calyptra vanishes, the capsule nods (8), and 

 the lid operculum (9) at the top opens, revealing wiftrin 

 a greenish dust. This consists of a multitude of tiny grains 

 or spores, soon to be scattered on the ground, and to serve 

 as seeds. After the operculum has fallen off, the mouth 

 (stoma) remains open, and is seen beautifully bordered by 

 a circlet of teeth. This is called the peristome (Gr. peri, 

 around, stoma, mouth). With a microscope we can see 

 that the teeth are blunt (10), and 64 in number.* 



Classification. At the top of the stem, before the fruit- 

 arises, we may often find a group of organs resembling and 

 indeed serving as a flower (2).f But being colorless and 



* In other kinds of Moss the number of the teeth is 4, 8, 16, 32 always some 

 power of 2. Sometimes the peristome is doable, the inner one consisting of as many 

 little hairs (cilice.) 



t In Fig. 1 (2) the artist has delineated a male, or sterile flower of Polytrichum 

 (for two kinds of flowers are developed by this Moss). In 4 is seen, greatly mag- 

 nified, the special organs (two antheridia, and o, 0, two paraphyses) of the sterile 

 flower. In 5, also greatly magnified, are seen the two pistilidia of a fertile flower, 

 from one of which the capsule arises, the other proving abortive ; 3 is one of the 

 leaves (sepals). 



