CHAPTER XVI 



BRYOPHYTES (MOSS PLANTS) 



Liverworts and Mosses 



General Discussion. — In the study of the Myxomycetes, 

 Bacteria, and Fungi, not much attention was given to evolution- 

 ary tendencies, for these groups are supposed to be degenerate 

 forms and have contributed nothing of importance in the way of 

 evolution. But in taking up the study of the Bryophytes, we 

 return to the study of evolution which will be emphasized 

 throughout the remaining groups, the aim being to see how 

 Flowering Plants could have originated. 



The Bryophytes include two large groups of plants — Liver- 

 worts ( Hepaticae) and Mosses (Musci) — although the term 

 refers to Mosses. The Mosses are more conspicuous and more 

 familiar to most people than the Liverworts, but they are no 

 more important in the study of evolution. 



The Bryophytes are of practically no economic importance. 

 They are of very little value for food and rarely harm other 

 plants. They make their own food and therefore do not need 

 to prey upon other plants. The only reason for studying them 

 is that they have contributed to evolution, and a knowledge of 

 them is necessary for an understanding of the higher plants. 



The Bryophytes are supposed to have originated from the 

 Algae, and the advancements made by the Algae, such as the 

 establishment of multicellular plant bodies, food-making by 

 photosynthesis, development of gametes and sex organs, and the 

 differentiation of gametes and other cells, are resumed and some 

 of them carried farther by the Bryophytes. 



Most Algae live in the water while the Bryophytes in most 

 part live on the land. The Bryophytes are considered the first 

 and most primitive land plants. The Algae are exposed to water 

 while most Bryophytes are exposed to the drying effects of the 

 air. Most Algae soon die when removed from the water and 

 exposed to the air, for they are not protected against loss of water 



405 



