356 GENERAL MORPHOLOGY OF PLANTS 



that of the liverworts, and shows that the mosses stand higher in 

 the scale of classification and development than the liverworts. 



509. Relationship of the liverworts and mosses. There 

 are, however, taken as a whole, very close relationships between 

 the liverworts and mosses, shown in the character of the sexual 

 organs, and especially in the capsule, though there are great 

 differences between such a simple one as is found in Riccia, 

 where the egg develops into a rounded mass of spores surrounded 

 by a single layer of sterile cells, and the very complicated capsule 

 (spore plant stage) of the higher mosses supported on a stalk. 

 The intermediate forms show intermediate steps in this speciali- 

 zation. The spore plant (or sporophyte) in all agrees, however, 

 in being dependent on the gamete plant for its nourishment, in 

 not possessing leaf-like outgrowths, and in the formation of a 

 capsule for the production of the spores. For these reasons the 

 liverworts and mosses together make up one of the great branches 

 of the plant kingdom, called the Bryophytes, or moss-like plants. 



510. ^Formula for the life history of liverworts and 

 mosses. The asexual stage in the liverworts and mosses is the 

 capsule (with the stalk when present) or spore plant (sporophyte), 

 and alternating with the first generation, the gamete plant 

 (gametophyte). The formula may be represented thus 



/anthendia sperm gamete\_ .. . , 

 Gametophyte< >Fertilized 



\archegonia egg gamete / 



egg 



Sporophyte asexual spores Gametophyte, etc., which re- 

 duced becomes 



G < / FE S asp G., etc. 

 * For reference. 



