. Animate creation : popular edition of "Our living world" : a natural history. Zoology; Zoology. THE ROTIFERS. 581 year old the roots are veritable flying buttresses. Remark how well adapted this plan is to finish the growth of the island, to bring it up to a safe height, when other elements shall be utilized. These flying buttresses catch all debris of the ocean, and hold it until a soil is formed. Now, birds come to roost here ; they bring seeds, which are deposited in the excre- ment. Among these seeds are several kinds of great convolvuli, morning-glory plants, whose habits are
. Animate creation : popular edition of "Our living world" : a natural history. Zoology; Zoology. THE ROTIFERS. 581 year old the roots are veritable flying buttresses. Remark how well adapted this plan is to finish the growth of the island, to bring it up to a safe height, when other elements shall be utilized. These flying buttresses catch all debris of the ocean, and hold it until a soil is formed. Now, birds come to roost here ; they bring seeds, which are deposited in the excre- ment. Among these seeds are several kinds of great convolvuli, morning-glory plants, whose habits are to run on the ground like a pumpkin vine. These great vines take root at intervals—many of them form resting-places for moving rubbish. Sand begins to collect. Innumerable agencies conspire to bring this low island to a greater height above water, when the land becomes dry; hence Dry Tortugas, in contra- distinction to Wet Tortugas, or wet land that has not yet reached the point of being above water. Once the surface has become somewhat permanently dry, other seeds germinate, and grasses appear—the beach-grasses, whose rootlets catch and hold the sands. Eventually a considerable soU is formed. The visitation of sea birds brings guano, shrubs appear, and then great ti-ees. Some of the older keys are heavily wooded with a variety of trees. By these processes it is supposed the larger portion of the State of Florida has been built R O T I F E R A. LTHOUGH the Rotifera, or Wheel Animalcules, are generally placed among the Infusoria, on account of their minute dimensions and aquatic habits, it is evident, from many peculiarities of their fonnation, that they deserve a much higher place, and in all probability constitute a class by themselves. They are caUed Wheel Animalcules on account of a curious structure which is found upon many of their members, and which looks very like a pair of revolv- ing wheels set upon the head. These so-called wheels ai-e two disc-like lobes, th
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Keywords: ., bookauthorbr, bookcentury1800, bookdecade1890, booksubjectzoology
