32 A FEEN BOOK FOR ETERTBODT 



still further cliaracterized by the thin membranaceous 

 texture of the fronds. In this group the tufts of spore- 

 cases are enclosed in a kind of receptacle. 



This receptacle is urn-shaped in the Bsistle Feens 

 (TricJiomanes) . (Fig. 21.) 



The receptacle is two-valved in the Pilmt Ferns 

 (^IlymenopTiyllum) . (Fig, 22.) 



In order to affix these characters more permanently on 

 the memory, they are tabulated in the following manner :^ 



Mg. 21. Fig. 22. 



First G-roup. — The spore-cases loitJiout a ring. 



Spore-cases or seed-vessels borne on a separate 



frond, in a simple spike . . Adder's Tongue. 

 In a branched spike .... Moonivort. 

 Spore-cases or seed-vessels borne on the upper part 



of a barren frond, which is hmnohedi— Osmund 



Ferns. 



Second G-rotjp. — The spore-cases surrounded by a 

 In the following the ring is vertical : 



* The youna: botanist must bear in mind that many of the terms employed 

 here are not rigidly and scientifically correct, but are the nearest approxima- 

 tion which popular language permits. 



