Minnesota Plant Life. 



151 



niae cannot be viewed as they were in the gemma-liverwort, as 

 little modified, specialized branches of the general plant-body, 

 but they must rather be considered to belong to the first-stage. 

 When they are produced upon a leaf or at the end of a stem, 

 the best explanation seems to be this: The first-stage of the 

 moss-plant is the most fundamental and is the original state of 

 the plant. The second-stage what is called the "moss-plant" 

 is a more or less highly organized reproductive branch. Then 

 any cell of the second-stage about to develop as a propagative 

 body would naturally grow out into the filaments of the first- 

 stage ; and this actually takes place when moss leaves or bits of 

 stem are separated from the rest of their body. But when 

 gemmae are produced it would seem that these filaments, grow- 

 ing out from the ordinary cells of the plant-body, have gained 

 the power of forming small, massive, bulging tubers in which 

 more nutriment can be stored than in the ordinary slender fila- 

 ments. So then the gemmae, although apparently borne upon 

 the body of the second-stage, should be considered as really be- 

 longing to the first-stage of the moss sexual plant. 



Hairy-capped mosses. A number of other forms must be 

 passed with brief mention. Among these are the hairy-capped 

 mosses, remarkable for the peculiar structure of their leaves, 

 for the formation of capsular plants during the summer and au- 

 tumn of one year and their maturation during the spring of the 

 next, and for the curious Robinson-Crusoe-like hoods that are 

 carried on the tops of the capsular plants. They are many of 

 them adapted to very dry localities and are common in pine 

 barrens. 



The second series of lid-mosses includes those forms in which 

 the egg-organs are developed near the axils of leaves rather than 

 terminally upon the stems. 



River-mosses. Here are the river-mosses, characterized by 

 their three-ranked arrangement of leaves without midribs and 

 the short stems of the capsular plants. Since the capsules are 

 formed below the surface of the water there is no necessity of 

 their being borne on long slender stems. The object of the 

 slender stem is to aid in wind-dissemination of spores and ob- 

 viously, then, short stems might be expected to support the 

 submerged capsules. 



