. Analysis of development. Embryology; Embryology. dp. Fig. 194. Sections through the skin of saddle region of a normal Lakenvelder pullet. 3 weeks after hatching, showing the structure of the fully differentiated skin and definitive feathers developing in situ. Delafield's hematoxylin, 10/u. A, X 75; B, X 100. b. Cells of the barb system; c, collar (thick ring of embryonic feather- forming cells); d, dermis or corium; dp, dermal papilla of feather; e, epidermis; em, erector muscles of feather; /, follicle cavity; m, striated muscles; p, pulp of feather; r, rachis. as being much more specific
. Analysis of development. Embryology; Embryology. dp. Fig. 194. Sections through the skin of saddle region of a normal Lakenvelder pullet. 3 weeks after hatching, showing the structure of the fully differentiated skin and definitive feathers developing in situ. Delafield's hematoxylin, 10/u. A, X 75; B, X 100. b. Cells of the barb system; c, collar (thick ring of embryonic feather- forming cells); d, dermis or corium; dp, dermal papilla of feather; e, epidermis; em, erector muscles of feather; /, follicle cavity; m, striated muscles; p, pulp of feather; r, rachis. as being much more specific than they are considered to be at the present time. The term induction has now been extended to include a variety of "organizing" influences from unspecific activation to the very specific organization of typical patterns in space and time. Inductive phenomena are by no means physiologically uniform. The Feather. The two classic methods that have been employed in general for demon- the origin of feather germs should be re- called. The first indication of the site of a prospective feather is seen in the meso- dermal portion of the dermis or corium, at approximately the fifth day of incubation, in the form of an aggregation or condensa- tion of cells immediately beneath the thin, two-layered epidermis. This condensation is the primordium of the dermal papilla and precedes any visible epidermal response, as. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Willier, Benjamin H. (Benjamin Harrison), b. 1890. Philadelphia, Saunders
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Keywords: ., bookcentury1900, bookpublisherphiladelphi, booksubjectembryology
