. A dictionary of birds . TeleoptileOF A Pigeon. Maguifled. C, Cutis; E, Epitrichium; M, Malpighian cells; JfiiVj,Middle stratum of inner half of the Malpighian mass of cells ; Outer half of Malpighian cells forming the follicle ; P,Pulp ; R-ni, Rami ; Sh. Sheath ; , corneum of thefollicle continued into at the surface of the skin. is gradually transformed into a delicatefilled with blood—the plasma necessary forepidermal parts. In fact, the pulp isthe nutritive organ of the Avholefeather. ,/■• The mantle of Malpighian cellswhich surrounds the pulp differentiatesitself
. A dictionary of birds . TeleoptileOF A Pigeon. Maguifled. C, Cutis; E, Epitrichium; M, Malpighian cells; JfiiVj,Middle stratum of inner half of the Malpighian mass of cells ; Outer half of Malpighian cells forming the follicle ; P,Pulp ; R-ni, Rami ; Sh. Sheath ; , corneum of thefollicle continued into at the surface of the skin. is gradually transformed into a delicatefilled with blood—the plasma necessary forepidermal parts. In fact, the pulp isthe nutritive organ of the Avholefeather. ,/■• The mantle of Malpighian cellswhich surrounds the pulp differentiatesitself into three strata of unequal thick-ness. The innermost and thinneststiatum forms a transparent sheath forthe pulp, and persists ultimately asthe series of caps or soul beforementioned. The middle stratum isthe thickest and becomes the featheritself, while the outermost forms atransparent and coherent cylindricalsheath, which encloses the groovingfeather, giving it its well-known spine-like appearance, until, peehng. Transverse Section of the sameFeather through MiM-^. Cells forming the future After-shaft ; C, Cutis ; Malpighian cellsof tlie follicle; Cells of the prin-cipal shaft; R, Rami; ./(. Sheath ; Stratum corneum of the follicle. FEA THERS 247 off as scurf, it sets free the rami of the young product. Whilethe papilla grows to the length the young feather is to reach, thecells of the middle stratum arrange themselves in longitudinal rows,causing the pulp to assume in transverse section a somewhat star-shaped appearance. These rows are transformed into the hair-likerami of which most Neossoptiles consist, and their formation pro-ceeds from the apex downwards, while the radii seem to beproduced by secondary splitting. Ultimately all the rami meetat the base of the feather and there form, with the basalportion of the sheath, a very short cylindrical tube, which is thecalamus of the Neossoptile, while the pulp having fulfilled itsfunction
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Keywords: ., bookauthorlyde, bookcentury1800, bookdecade1890, booksubjectbirds
