532 



LIFE-HISTORIES 



Finally, in a considerable varietj' of ways means are provided for 

 scattering the spores as far as possible and under the most favorable 

 conditions for giving the new plants a good fair start. 



Bryophyta arc distinguished by having archegonia on lobed or pseudo- 

 leafy gametophytes which bear sporophytes lacking true roots, stems, 

 and leaves. 



Flo. 357. — Addcr-toiigue, A, and grape-fern, B (Opiiioglossum rulf/atum 

 and Botrychium Lunaria, Adder-tongue Family, Opliioglossacca). 

 Sporophytes showing roots (w), stem (sO. leaf-stalk (6s), point (x) at 

 which leaves branch to form a foliage-blade (6) and a spore-bearing 

 division (/). Two-thirds natural size. (Sachs.) — Not very conmion 

 but widely distril:>utcd in mostU^ open ground. 



192. The ferns (Class FiliciiiEe). Our most primitive 

 ferns are repre.sented by adder-tongues (Ophioglossum) and 

 grape-ferns (Botrychium, Fig. 357). 



Unfortuntitely their life-histories arc not yet fully known owing 

 to peculiar difliculties in tracing the germination of the spores. 

 The gametophyte is subterranean (Fig. 3.5S) and at least when 

 mature it is saprophytic. Exoci)t for its lack of chlorophyll it is 

 not a little lik(^ the gametophyte of Riccia. The gametophyte of 



