. A laboratory manual and text-book of embryology. Embryology. Yolk cavity. Fig. 17.—Diagrams showing the blastulae: A, of Amphioxus; B, of frog, and C of chick; D, blastodermic vesicle of mammal. In Primates, but one stage in segmentation has been observed. This, a four-celled ovum of Macacus nemestrinus figured by Selenka, shows the cells nearly equal and oval in form. This ovum was found in the oviduct of the monkey and shows that, in Primates and probably in man, segmentation as in other mammals takes place normally in the oviducts. THE FORMATION OF THE ECTODERM AND ENTODERM The blastula a
. A laboratory manual and text-book of embryology. Embryology. Yolk cavity. Fig. 17.—Diagrams showing the blastulae: A, of Amphioxus; B, of frog, and C of chick; D, blastodermic vesicle of mammal. In Primates, but one stage in segmentation has been observed. This, a four-celled ovum of Macacus nemestrinus figured by Selenka, shows the cells nearly equal and oval in form. This ovum was found in the oviduct of the monkey and shows that, in Primates and probably in man, segmentation as in other mammals takes place normally in the oviducts. THE FORMATION OF THE ECTODERM AND ENTODERM The blastula and early blastodermic vesicle show no differentiation into layers. Such differentiation takes place later in all vertebrate embryos and the three primary germ layers, ectoderm, entoderm and mesoderm, are formed. From these three layers all of the body tissues and organs are derived. Gastrulation.—In the case of Amphioxus and amphibia the entoderm is. 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 Prentiss, Charles William, 1874-1915. Philadelphia, London, W. B. Saunders
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectembryology, bookyear1
