. Birds . ANGES WHICH TAKE PLACE DURING INCUBATION PROVISION MADE FOR THE BIRDS FIRST HATCH-ED—PARENTAL CARE. It will now be desirable to consider particularly thehatching of eggs by the parent bird. Our poet Mont-gomery has said, in reference to the pelicans he has sobeautifully described :— The noble birds, with skill spontaneous, framedA nest of reeds among the giant -waved in lights and shadows oer the , in sweet thraldom, yet unweening why,The patient dam, who neer till now had knownParental instinct, brooded oer her eggs,Long ere she found the curious secret out,That
. Birds . ANGES WHICH TAKE PLACE DURING INCUBATION PROVISION MADE FOR THE BIRDS FIRST HATCH-ED—PARENTAL CARE. It will now be desirable to consider particularly thehatching of eggs by the parent bird. Our poet Mont-gomery has said, in reference to the pelicans he has sobeautifully described :— The noble birds, with skill spontaneous, framedA nest of reeds among the giant -waved in lights and shadows oer the , in sweet thraldom, yet unweening why,The patient dam, who neer till now had knownParental instinct, brooded oer her eggs,Long ere she found the curious secret out,That life was hatching in their brittle shells—Then, from a wild rapacious bird of prey,Tamed by the kindly process, she becameThat gentlest of all living things—a mother. Various indeed are the situations in which hen-birdspass through this remarkable process. The engraving THE WOOD WARBLER. shows the wood warbler in her g-round nest; whileothers may be discovered in very different circumstances. i^ ^. The Wood Warbler. Our chief knowledge of incubation arises, however, fromthe attention that has been given to the domestic hen ;and this, therefore, we proceed to notice. In a few hoursafter the hen has been brooding over her eggs, a con- 54 CHANGES DURING INCUBATION. siderable alteration takes place. The form of the em-bryo changes ; it acquires length, and its progress is seenby a blood-vessel issuing from either side, branchinginto numerous smaller ones, which unite at their ter-mination, and become a boundary on the covering ofthe yolk. The chick is the centre of this net-work ofvessels; and as the embryoincreases so do they multi-ply, until they nearly pervadethe membrane of the appears from a recent ex-periment, that when these ves-sels are first formed, and pro-bably before, each branch is ac-companied by a vessel carry-ing yolk into the body of thechick; and thus there is asupply for its sustenance and growth. Early Change. Between the third and fourth day a
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Keywords: ., bookauthorreligioustractsociety, bookcentury1800, bookdecade1840
