. The biology of the frog. Frogs. 1SS THE BIOLOGY OF THE FROG Junius, they occur on all parts of the skin, although they may be comparatively scarce in certain situations. Like the mucus glands they possess a muscular and a connective tissue coat outside the layer of epithelium. The chief differences in the two types of glands, with the exception of size and the thickness of the tunics, lies in the secreting cells. Engelmann described the epithelium as M. G M. G. •P. G P. G Fig. 50.—Section across a dermal plica of Rana esculenta. M. G, mucus glands; P. G, poison glands; the granular epitheliu
. The biology of the frog. Frogs. 1SS THE BIOLOGY OF THE FROG Junius, they occur on all parts of the skin, although they may be comparatively scarce in certain situations. Like the mucus glands they possess a muscular and a connective tissue coat outside the layer of epithelium. The chief differences in the two types of glands, with the exception of size and the thickness of the tunics, lies in the secreting cells. Engelmann described the epithelium as M. G M. G. •P. G P. G Fig. 50.—Section across a dermal plica of Rana esculenta. M. G, mucus glands; P. G, poison glands; the granular epithelium has an indefinite outline and shows no cell walls. (After Gaupp.) consisting of cylindrical cells nearly filled with granules. The boundaries of the cells apparently disappear under cer- tain conditions of secretion, the epithelial lining forming a continuous irregular layer of protoplasm (Gaupp). The secretion of the poison glands is a whitish fluid with a burning taste. It may be caused to exude from the skin, especially of the bullfrog, by placing the animal under chloroform. Of its properties in the frog comparatively little is known. Paul Bert found that a goldfinch which was inoculated with the dermal secretion of Rana esculenta died. 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 : The Macmillan company
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Keywords: ., bookauthorholmessamueljsamuelja, bookcentury1900, bookdecade1920
