28 



A FERN BOOK FOR EYERYBODY. 



The principal features which may be employed to dis- 

 tinguish the three genera which compose this group are — 



The spore-cases are arranged on a simple and un- 

 branched spike in Adders' Toi^auES {Oj)Mofflossum), 



The spore-cases are arranged on a compound or 

 branched spike in Moonworts (^Botryclimrri). 



The spore-cases are clustered upon the branched or 

 metamorphosed upper portion of an otherwise barren 

 frond in Osmund Ferns {Osmunda), 



Fig. 11. 



The general character of the spore-cases in this group 

 are represented in figs. 5 and 11. 



The second and larger group contains all the genera 

 which are 



Annulate {with a ring). 



That we may render our analysis of this group evident 

 to those who are not professedly scientific, it will be 

 necessary to resort to a further subdivision into minor 

 groups. 



If the spore-cases of all the species could be examined 

 in succession, it would be observed that in a few of them 

 the ring is oblique^ whilst in the majority of them the 

 ring is vertical. Thus we are enabled to remove the sub- 

 group with oblique rings for future consideration, and, for 

 the present, deal only with those genera in which the ring 

 is vertical. 



As the sub-group still reserved is a large one, it will 

 be essential to find some other character which is common 

 to a few of the genera, and not present in the others. If 

 we look at the clusters of spore-cases, which we have 

 already observed are called sori, and which are arranged 

 on the back or at the margins of the fronds, it will be ob- 

 served that in some instances the tufts are quite naked, 



