. The elements of embryology. Chickens -- Embryos. 234 THE DEVELOPMENT OF THE SKULL. [CHAP. Fig. 71. to Embryonic Skull of a Fowl during the Second Week of Incubation (Third Stage) from below. (From Parker.) The figure is intended to shew the cartilaginous skull with its ossifications, and also the splint bones which have commenced to be formed independently of the cartilaginous cranium. The parts of the lower jaw and hyoid are omitted. The following letters refer to the cartilaginous cranium and its ossifications. pn prenasal cartilage, pa palatine bone (which has already become ossified). pr
. The elements of embryology. Chickens -- Embryos. 234 THE DEVELOPMENT OF THE SKULL. [CHAP. Fig. 71. to Embryonic Skull of a Fowl during the Second Week of Incubation (Third Stage) from below. (From Parker.) The figure is intended to shew the cartilaginous skull with its ossifications, and also the splint bones which have commenced to be formed independently of the cartilaginous cranium. The parts of the lower jaw and hyoid are omitted. The following letters refer to the cartilaginous cranium and its ossifications. pn prenasal cartilage, pa palatine bone (which has already become ossified). pr/ pterygoid (also ossified), nc' notochord visible in the post-pituitary space. Both the notochord and the post-pituitary space would be in reality per- fectly concealed by the plate of bone bt, but have been diagrammatically re- presented as if they were visible through it. nc end of notochord appearing beyond the occipital condyle, q quadrate, as alisphenoid. ic internal carotid, ty tympanic cavity, psc posterior semicircular canal. 8 foramen for passage of eighth nerve. 9 foramen for passage of ninth nerve, eo centre of ossification for the occipital, so supraoccipital region, fm foramen magnum. The following letters refer to the splint bones. px premaxillary. mx maxillary, pmx process inwards from the premaxillary to form the maxillo-palatine. j jugal. qj quadrato-jugal. rbs sphenoidal rostrum. It 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 Foster, M. (Michael), Sir, 1836-1907; Balfour, Francis M. (Francis Maitland), 1851-1882. London, Macmillan and co.
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Keywords: ., bookcentury1800, bookdecade1870, bookpublisherlondo, bookyear1874
