452 



REPRODUCTIVE ORGANS. 



If it is altogether subordinate to reproduction, we may expect the 

 occurrence of far more simply constituted ferns than we are yet ac- 

 quainted with. In fact we may expect a form reduced to an axis, a few 

 ramenta, a frondose dilatation, and one punctum of reproductive 

 organs. 



With respect to duration, each frond is analogous to a single seta 

 of a moss, it has definite limits, and is unlike the fronds of certain 

 Hepaticse, which are capable of compound growth ; or if this is the 

 case in ferns, as it is in viviparous ferns, the new formation becomes 

 separated from the frond, as a Phasnogamous gemma does. This is 

 a question of importance, as perhaps it may prove that all the foliace- 

 ous forms, except Lycopodium, Equisetum, and Chara, are frondose ; 

 the dorsal situation is in favour of this assumption, since in all the 

 genuine frondose forms, the reproductive organs of both kinds ori- 

 ginate immediately from the under surface, although they may pro- 

 trude through the upper. 



I here ask, is there not primd facie evidence that these organs have 

 peculiar functions ; a peculiar form, attended with peculiar changes, 

 must have peculiar functions ; and will any one show me in any single 

 instance, like circumstances to the like extent, in any of those organs 

 called hairs ? By the bye, ferns themselves may prove that however 

 like these are to certain forms of hair, yet that their functions are 

 different, because the glandular hairs of ferns do not undergo the 

 same alterations, and are evidently nothing but hairs, probably secre- 

 tory. 



\9th. — In Ceterach the same thing occurs precisely, with this 

 difference, that the capita of the ramenta are highly developed ; and 

 still more, that the terminations of each pinnula of the young frond, 

 are mere scales without a terminal head. 



So that almost all the scales of the under surface of the lobes of 

 the mature frond, are mere scales. The peculiar ramenta are to be 

 looked for along the insertion of each pinna, and along the rachis, in 

 which all have the peculiar structure. 



At the time that these scales are commencing their development, 

 the peculiar ones are at the age of mature perfection, so far as func- 

 tion goes. No one can look at a young pinnula at this epoch and ob- 

 serve the evident capitation of each ramentum, the inflexion of its apex, 

 so that the head is brought into contact with the frond, without sus- 

 pecting that they have the same relation of cause to the appearance 

 subsequently of the thecse or capsules. It is curious that the colour 



