350 



GENERAL MORPHOLOGY OF PLANTS 



with sterile tissue, and also surrounded by sterile tissue. These 

 tissues together form an elliptical body which is suspended in 



- 3 1 2. 



Fig. 313. 



Funaria hygrometrica. A , a young leafy stem^-, The mouth of the capsule A' of Fonti- 

 with the calyptra c. B, a plant g- with the al- palis antipyretica. Outer peristome ap, 

 most mature sporogpnium, of which s is the seta, inner peristome ip. (After Sachs.) 

 f the capsular portion, c the calyptra. C, longi- 

 tudinal section of the capsular portion dividing it 

 into two symmetrical halves; d the lid, a the 

 annulus, / the peristome, c, d the columella, h 

 air space, s archesporium. (After Sachs.) 



an air chamber within the capsule by delicate threads (fig. 312). 

 The spore-bearing tissue consists of a single layer of mother cells, 

 each one of which forms four spores. 



503. Life history of the mosses. The life history of the 

 mosses is as follows. The spores germinate and produce a much- 

 branched filamentous growth, the protonema, which means first 

 thread. This protonema resembles superficially some of the 

 filamentous green algae, but the cross walls are often oblique and 

 this serves at once to distinguish them. The protonema forms a 

 thin or rather dense web on the ground or on rotten wood. The 

 leafy-stemmed moss plant arises from this as a stouter branch, 

 with the oblique walls regular and close together. Rhizoids are 

 developed from the base of the leafy stem and sometimes quite 



