To naked Thecæ.
To indusiate as Asplenia, etc.)
But however erroneous these views may be, they will still have been of service if general attention is directed by them to plants, in consequence of the suggestions they make. The time now thrown away on isolated species, the station of which, still does not become fixed, when devoted to the philosophical examination of ferns, will rescue botany from one of its numerous reproaches. It is strange that such should exist to the greatest degree in all those families stamped by nature as most distinct. Those chaoses Polypodium, Aspidium, Davallia, would then undergo distinct creation, and the primary divisions of the family would become fixed; and we should then be spared the reproach of drawing characters from organs, of the nature and functions of which we are quite ignorant of, and of the importance of which in a science of demonstration like that of botany, it is impossible to judge, without a true knowledge of structure.
Vide Lindley’s Introd. ed. 2, 407, for the protest of Greville and Arnott.
What is the most comprehensive definition of a pistil. A case in which the future organs of reproduction are developed; and here is a most curious circumstance, namely, that though the calyptra, which is a genuine pistillum containing an ovulum, becomes torn up from its base, yet it remains in contact with that part of the seta in which the sporules are developed until these make their appearance, or even later!! so that one might as well deny a pistillum to a Reseda, or Leontice, as deny it to these plants on the strength of its being torn from its attachments. Sprengel’s objections are worthy only of being noticed from their having been quoted by Lindley. The vagueness of his statement destroys all weight.
His objections in all cases amount to the fact, that the stellulæ or buds containing the anthers are capable of growth. So is the prolongation of an axis of Ananassa.
A Gemma has a general character in its formation as well as an anther, or as pollen; one is a congeries of cellular tissue, with or without vessels, the other a sac consisting of a single cell containing active molecular matter. As an anther producing a single grain of pollen is not inconsistent with our notions of structure, so neither is an anther consisting of a single grain of pollen.
Will any one show me an instance of a proved gemma taking upon itself the form of one of these anthers? Will any show an instance of a sac containing fluid matter capable of growth after dehiscence. The real gemmæ of the Hepaticæ puts the question of gemmæ out of doubt. Is there any plant existing with two sorts of gemmæ, so differently constituted? Many phænogams have gemma in addition to sexes, so have Hepaticæ. Which is the most probable? That they should have no sexes, reproductive organs, and two sorts of gemmæ, or sexes, reproductive organs, or gemmæ of one evident kind?
I cannot adopt the belief of any one having seen the germination of the powder in the axillary bodies, that is, if applicable to the organs I take for anthers.
(Memorandum.—To draw up a parallel between the two sets of organs, and the steps followed in the development of each.)