. On the anatomy of vertebrates. Vertebrates; Anatomy, Comparative; 1866. § 11. Dcvclopement of hone.—The primitive basis, or ' l)liis- tema,' of bone is a sul)transparent glairy matter containing numcrons minute corpuscles. It progressively 9 acquires increased firaniess; sometimes assuming a membranous or ligamentous state, usually a gristly consistence, before its conversion into bone. The change into cartilage is noted b}^ the a|)pcarance of minute nucleated cells ; which increase in number and size, and are a<iiire<i-ated in rows, with intercellular tracts, where the ossi- fication
. On the anatomy of vertebrates. Vertebrates; Anatomy, Comparative; 1866. § 11. Dcvclopement of hone.—The primitive basis, or ' l)liis- tema,' of bone is a sul)transparent glairy matter containing numcrons minute corpuscles. It progressively 9 acquires increased firaniess; sometimes assuming a membranous or ligamentous state, usually a gristly consistence, before its conversion into bone. The change into cartilage is noted b}^ the a|)pcarance of minute nucleated cells ; which increase in number and size, and are a<iiire<i-ated in rows, with intercellular tracts, where the ossi- fication is abovit to begin, as in fig. 9. These rows, in the cartilaginous basis ol' long bones, are vertical to its ends : in that of fiat bones , -11 • mi Section of temponiry cai-tl- they are vertical to the margm. The cells I'lsc, iviiicn bas umingono ,;,,, , f, •? ,• a , the last sl;igo towards ossl- tin-tncst trom the seat ot ossifacation are flat- tkation. cl. tened and in close contact; nearest that scat they become enlarged and separated. In fig. 9, a is the intercellular or ' intercolumnar' tissue ; h the enlarged cell-wall; e the nucleus. The first appearance of bone is that of minute granules in tlie intercolmnnar and intercellu- lar tissue, fig. 10, II. Canals are next formed in the bone, liy absorp- tion, which ultimately receive blood- vessels, and become the ' vascular canals.' The immediate nutrition of Ijone is provided for by the produc- tion of minute ' plasmatic canals ' fi'om the vascular ones. In most fishes the plasmatic canals are free from partial dilata- tions, and appear as in the magnified section of bone, fig 11; where a shows the area of the ' -vascular canal,' and b the orifices of the ' jdasmatic canals,' exposed in a longitudinal section of a vascular canal. In some fishes, e. g. the Garpike {Belone), partial dilatations do occur in the plasmatic canals, of the form shown in fig. 12, d; and in a Sea-l)ream (Siirf/us) of that marked c ;
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Keywords: ., bookauthorowenrichard18041892, bookcentury1800, bookdecade1860
