Narrative of a Survey of the Intertropical and Western Coasts of Australia eBook

Philip Parker King
This eBook from the Gutenberg Project consists of approximately 494 pages of information about Narrative of a Survey of the Intertropical and Western Coasts of Australia.
on the surface of an anthera, distant from the female flower; and with this economy, a corresponding enlargement of the contained particles or fovilla might also be expected.  On examining these particles, however, I find them not only equal in size to the grains of pollen of many antherae, but, being elliptical and marked on one side with a longitudinal furrow, they have that form which is one of the most common in the simple pollen of phaenogamous plants.  To suppose, therefore, merely on the grounds already stated, that these particles are analogous to the fovilla, and the containing organs to the grains of pollen in antherae of the usual structure, would be entirely gratuitous.  It is, at the same time, deserving of remark, that were this view adopted on more satisfactory grounds, a corresponding development might then be said to exist in the essential parts of the male and female organs.  The increased development in the ovulum would not consist so much in the unusual form and thickening of the coat, a part of secondary importance, and whose nature is disputed, as in the state of the nucleus of the seed, respecting which there is no difference of opinion; and where the plurality of embryos, or at least the existence and regular arrangement of the cells in which they are formed, is the uniform structure in the family.

(Footnote.  Mem. de l’Acad. des Scien. de Paris 1775 page 518.)

The second view suggested, in which the anthera in Cycadeae is considered as producing on its surface an indefinite number of pollen masses, each enclosed in its proper membrane, would derive its only support from a few remote analogies:  as from those antherae, whose loculi are sub-divided into a definite, or more rarely an indefinite, number of cells, and especially from the structure of the stamina of Viscum album.

I may remark, that the opinion of M. Richard,* who considers these grains, or masses, as unilocular antherae, each of which constitutes a male flower, seems to be attended with nearly equal difficulties.

(Footnote.  Dict.  Class. d’Hist.  Nat. tome 5 page 216.)

The analogy between the male and female organs in Coniferae, the existence of an open ovarium being assumed, is at first sight more apparent than in Cycadeae.  In Coniferae, however, the pollen is certainly not naked, but is enclosed in a membrane similar to the lobe of an ordinary anthera.  And in those genera in which each squama of the amentum produces two marginal lobes only, as Pinus, Podocarpus, Dacrydium, Salisburia, and Phyllocladus, it nearly resembles the more general form of the antherae in other Phaenogamous plants.  But the difficulty occurs in those genera which have an increased number of lobes on each squama, as Agathis and Araucaria, where their number is considerable and apparently indefinite, and more particularly still in Cunninghamia, or Belis,* in which the lobes, though only three in number, agree in this respect, as well

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