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 function goes. No one can look at a young pinnula at this epoch and observe the evident capitation of each ramentum, the inflexion of its apex, so that the head is brought into contact with the frond, without suspecting that they have the same relation of cause to the appearance subsequently of the thecæ or capsules. It is curious that the colour of the scales is the same as that of the ramenta, in which the colour is developed from above downwards, a peculiarity as it appears to me.
The frond of Ceterach is very frondose-looking, it has stomata on its under surface, and the cells of the cuticle very sinuate. There can be no doubt of the propriety of including the nature of these ramenta and scales in its generic character.
I can see nothing peculiar in the situation of the scales or ramenta to suggest the reason of the situation of the capsules.
In several cases, each pinna appears to have scales only which become barren lobes? the scales and ramenta have the same imbricate situation. In this country it will be useless to expect more proofs. But the four genera alluded to afford evidence enough, and sufficient to show that these ramenta are formed with reference to some important function, that their universality is incompatible with any functions of such minor degree as are attributed to them by those who represent them to be scales or hairs.
To those who require proof of the existence of the complex male organ of Phænogams, or of a male of that form with which only they are familiar, I do not address myself; but to the philosophic botanist, who expects to meet with in the lower orders of plants, a lower organization, one with a tendency of reduction to the essential elements, and who bears in mind the comparative anatomy and structure of similar bodies in adjoining, or not very distant groups, I beg leave to suggest the intimate study of the ramenta of Ferns.
Various as the situation of the fructification is, in three out of the above four genera, yet the initial arrangements are precisely the same. The various forms therefore may not depend proximately on fructification itself, but on the peculiar growth given to the species, in the same way in fact as we have the numerous modifications of the theca in mosses, etc. and the infinite modifications of the carpels in Phænogams.
(Attention is particularly pointed to those ferns which have general capsules or involucres.
Above all to the Cyatheoid forms.
To Ophioglossum.