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. 
B, protonema of Funaria hygrometrica, a moss; h, a well-developed primary 
shoot ; A, rudiment of a leaf-bearing axis, or ordinary moss plant, like Fig. 202 ; 
w,aroot-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 
