190 A. TEXT-BOOK OF BOTANY 
speaks of a moss and a fern, the gametophyte is referred 
to in the former case and the sporophyte in the latter. 
This means that, in passing from mosses to ferns, plants 
have transferred the chief work of food manufacture from 
the gametophyte to the sporophyte, which has thus become 
the conspicuous generation. The leaves of mosses, there- 
fore, are gametophyte leaves; while the leaves of ferns are 
the first sporophyte leaves. A common and brief statement 
of the contrast between the two groups is that mosses have 
a leafless and ferns a leafy sporophyte. How the leafless 
sporophyte has become a leafy one is an interesting but un- 
Fig. 182.—Sporangia of ferns: -1, elongated sori, with pocket-like indusia; B, round 
sori, with shield-like indusia. 
