264 



PRACTICAL BOTANY 



part of the life cycle which produces the asexual spores is 

 called the sporophyte, meaning an asexual spore-producing 



plant. The part which pro- 

 duces the obspore is called 

 the gametophyte, the gamete- 

 producing plant. The spo- 

 rophyte, therefore, is the 

 asexual generation of moss, 

 and the gametophyte is the 

 sexual generation. The rela- 

 tion that these two bear to 

 one another in the complete 

 life cycle is called the alter- 

 nation of generations. 



The fact that the proto- 

 nema and leafy shoot are 

 distinct structures does not 

 introduce a third genera- 

 tion, since one 

 of those struc- 

 tures grows 

 from the other 

 without the in- 

 tervention of 



FIG. 221. Sphagnum 



A, an entire plant which hears capsules upon its tallest branch (natural size) ; B, two 

 sporophyte capsules and stalks enlarged ; C, tip of a vegetative branch enlarged 



