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If all pedunculated cirripedes had become extinct, and they have suffered far more extinction than have sessile cirripedes, who would ever have imagined that the branchiae in this latter family had originally existed as organs for preventing the ova from being washed out of the sack?
Now social capital will always fall sooner or later to those communities whose members use it most prospectively, who are willing to forego, to quite an extent, present enjoyment, and look for future return. The same is true of all development. Sessile forms and mollusks, and, in a less degree, crabs and reptiles, worked for immediate return.
The cones are about three or four inches long, and two and a half wide, growing in close, sessile clusters among the leaves. The species attains its noblest form in filled-up lake basins, especially in those of the older yosemites, and so prominent a part does it form of their groves that it may well be called the Yosemite Pine.
In the immediate present things are mean, dulled by wont, and perhaps even nauseating because of familiarity. There must be a change of scene to see the world; man is not sessile but locomotor; and the moment his life becomes migratory all the restraints and responsibilities of settled life vanish. It is possible to steal and pass on undiscovered and unsuspected, and to steal again.
Flowers 3½ inches across, produced from the end of July to the end of September, bright golden yellow; leaves large, ovate, tapering from the middle to both ends; stalk leaves sessile and nearly connate, that is, clasping the stalk by their opposite base. The plant spreads rapidly by running rootstocks, and ripens seed in abundance.
And, as if to make the case as striking as possible, this cirripede was a Chthamalus, a very common, large, and ubiquitous genus, of which not one species has as yet been found even in any tertiary stratum. Still more recently, a Pyrgoma, a member of a distinct subfamily of sessile cirripedes, has been discovered by Mr.
You can hardly have failed to notice how closely the gastrula corresponds to a hydra, and many facts lead us to believe that the still earlier ancestor of the hydra was free swimming, and that the tentacles are a later development correlated with its adult sessile life. Yet we must not forget that the hydra is even now not quite sessile, it moves somewhat.
Now for a flower. The stem which we have picked is the stem of perennial Rye Grass. The blossom, we see, consists of several small spikelets; there are eighteen on our stem. They grow alternately on two opposite sides of the stem, first one on one side, then one on the other. They have no stalk of their own; they are sessile or seated on the stem.
So again the two main divisions of cirripedes, the pedunculated and sessile, which differ widely in external appearance, have larvae in all their several stages barely distinguishable.
These cirripedes have no branchiæ, the whole surface of the body and sack, including the small frena, serving for respiration. The Balanidæ or sessile cirripedes, on the other hand, have no ovigerous frena, the eggs lying loose at the bottom of the sack, in the well-enclosed shell; but they have large folded branchiæ.
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