4o6 THE NON-VASCULAR PLANTS 



This so-called moss fruit is a sporogonium. It bears 

 spores in the capsule-shaped enlargement at the top. This 

 spore-containing enlargement is 

 called the capsule, the stalk which 

 bears it is called the seta, and the 

 third part of the sporogonium, which 

 is hidden in the top of the moss 

 stem, is called the foot. The spores 

 escape from the ripe capsules and 

 are scattered by the air. When they 

 germinate, they produce a filamen- 

 tous growth which looks Uke an alga. 

 This growth is called protonema. 

 A protonema can always be told 

 from filamentous algag by the fact 

 that its cross walls are' diagonal in- 

 stead of straight. (See Figure 203.) 

 Buds appear upon the protonema, 

 and these buds develop into the 

 erect, leafy moss plants. 



The archegonia and antheridia of 

 Fig. 202. - Poiyirichum. a mosses are found at the tops of the 

 common moss bearing what leafy stems. (See Figures 204 and 



is known as pigeon wheat. . \ c i" i. • j 



Each of these "fruits" of ^^^O _ Sometimes archegonia and 

 the "wheat" is asporogo- antheridia are found on the same 

 nium Note the long seta ^^^^ sometimes On Separate plants. 



and the capsules. The foot '■ _ i sr 



is embedded in the apex of The archegonia of mosscs are longer 

 the stem of the leafy part.— -^nd morc slender than those of liver- 



AJter Hunter. 



worts and the antheridia are club- 

 shaped. After fertilization the oospore develops into the 

 sporogonium, whose three parts have already been noted. 

 The spore-producing part of the sporogonium is much less 



