. The biology of the frog. Frogs. io6 THE BIOLOGY OF THE FROG CHAP. The lining of the mouth cavity is formed from an invagin- ation of ectoderm, the stomodeum, which pushes in until it breaks through into the archenteron. A similar ectodermal invagination, the proctodeum, forms the lining of a small part of the posterior end of the alimentary canal. The lens and Ms c. FlG. 26. — Cross section of a frog embryo. AR, archenteron; MS, meso- blastic somites; N, notochord; NS, neural crest; M, medullary tube; PR, pronephros ; SN, subnotochordal rod ; SO, SP, somatic and splanch- nic mesoderm. (From
. The biology of the frog. Frogs. io6 THE BIOLOGY OF THE FROG CHAP. The lining of the mouth cavity is formed from an invagin- ation of ectoderm, the stomodeum, which pushes in until it breaks through into the archenteron. A similar ectodermal invagination, the proctodeum, forms the lining of a small part of the posterior end of the alimentary canal. The lens and Ms c. FlG. 26. — Cross section of a frog embryo. AR, archenteron; MS, meso- blastic somites; N, notochord; NS, neural crest; M, medullary tube; PR, pronephros ; SN, subnotochordal rod ; SO, SP, somatic and splanch- nic mesoderm. (From Morgan, after Marshall.) cornea as well as the retina of the eye, and the vesicle of the inner ear, also take their origin from this layer. Organs from the Entoderm. - The entoderm, or the germ layer which is invaginated within the egg, gives rise to the lining of the alimentary canal and of all organs which. 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 Holmes, Samuel J. (Samuel Jackson), 1868-. New York, London, Macmillan
Size: 1694px × 1475px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorholmessamueljsamuelja, bookcentury1900, bookdecade1910
