CRYPTOGAMS 349 
406. The sporophyte. — The spores found in such abun- 
dance on the fertile pinne are all alike, and each one is 
capable of germinating and continuing the work of reproduc- 
tion as effectually as the sexual spores of the bryophytes. 
The fertile frond, or part of a frond, on which they are borne 
is called a sporophyll (spore-bearing leaf), and the entire 
plant is the sporophyte, which, with its crop of spores, makes 
up one generation. 
It is important to observe that in the ferns and in all pteri- 
dophytes the sporophyte is the conspicuous and _ highly 
organized body that is commonly recognized as the normal 
growing plant; while with the bryophytes just the reverse 
holds true, —the sexual generation, or gametophyte, repre- 
sents the normal plant structure, while the sporophyte is 
an insignificant appendage 
which never attains an 
independent existence. 
Broadly speaking, in bryo- 
phytes, it is a spore fruit ; 
in the pteridophytes and 
spermatophytes a highly 
developed plant. 
407. The gametophyte. 
— When one of these AIDES Figs. 501, 502. — Prothallium of a common 
ual spores germinates, it fern (Aspidium): 501, under surface, showing 
produces, not a fern plant, Tires 7h antherdia, an, and srchegoni, 
like the one that bore it, phyte, showing rhizoids, rh, young sporo- 
ne x small, heart-shaped phyte, with root, w, and leaf, b. 
body like that shown in Fig. 501. Examine one of these bod- 
ies carefully with alens. Observe that there are no veins nor 
fibrovascular bundles, and the whole body of the plant seems 
to consist of one uniform tissue. Compare it with the forked 
apex of a branching thallus of a liverwort. Do you perceive 
any points of similarity? The two are, in fact, morphologi- 
cally the same. This heart-shaped body is called a prothal- 
lium, and is the gametophyte of the fern. It may be of 
501 502 
