240 



ELEMENTS OF BOTANY. 



produces the urn or spore-capsule, and this is really a new 

 plant. It remains attached to the parent plant and is nour- 

 ished by it, does not grow to any considerable size, but develops 

 a great number of Spores in its interior. These spores when 

 fully formed are set free, germinate, and produce a thread- 

 like protonema, which at length grows into the fully developed 

 moss plant. The two generations, then, are the moss, with 

 its rather complicated reproductive apparatus, and the urn, 



Fig. 206. 



jB, protonema of Fwnaria hygrometrica, a mo^s ; h, a well-developed primary 

 shoot ; K, rudiment of a leaf-bearing axis, or ordinary moss plant, like Fig. 202 j 

 w, a root-hair. (Magnified about 90 diameters.) 



destitute of such apparatus but filled with spores which are 

 merely the product of continued cell-division in the interior 

 of the spore-capsule. 



298. Nutrition in Mosses. — Mosses, like the higher plants, 

 draw their food supply partly in a liquid form from the earth 

 and partly in a gaseous form from the air. It is interesting 

 to notice, in passing, that one of the best plants with which 



