CRYPTOGAMS 351 
bryophytes, and may be represented by the same formula. 
The chief difference is in the relatively much greater im- 
portance of the sporophyte, which may be expressed by 
putting it first: — 
£9. fy 
sS— 0o— a o00s—> S—> oa > 00s —>S—0—>G ete. 
am mg 
But some of the pteridophytes— of which the Selaginella 
offers'a conspicuous example — have differentiated their 
\ s A SS uN kx 
Ci en ee. 
my J 
504 507 
Fries. 504-508. — A kind of pteridophyte (Selaginella martensiz) with its organs of 
fructification: 504, a fruiting branch; 505, a microsporophyll with a microsporaa- 
gium, showing microspores through a rupture in the wall; 506, a megasporophyll 
with a megasporangium; 507, megaspores; 508, microspores. (From CoULTER’S 
“ Plant Structures.’’) 
