. The biology of the frog. Frogs. 2l6 THE BIOLOGY OF THE FROG CHAP. lining of cells, some of which (spermatogonia^ spermatocytes, and spermatids) represent stages in the formation of sperma- tozoa ; others form the so-called " follicle-cells," and the flattened cells described by Bertacchini, which lie next to. FlG. 59. — A, cross section of one of the tubules of the testis ; sp, bundles of spermatozoa; , epithelial lining of the tubule. B, stages in the de- velopment of spermatozoa. (After Parker and Parker.) the outer membrane. The follicle cells form a sort of wall around group
. The biology of the frog. Frogs. 2l6 THE BIOLOGY OF THE FROG CHAP. lining of cells, some of which (spermatogonia^ spermatocytes, and spermatids) represent stages in the formation of sperma- tozoa ; others form the so-called " follicle-cells," and the flattened cells described by Bertacchini, which lie next to. FlG. 59. — A, cross section of one of the tubules of the testis ; sp, bundles of spermatozoa; , epithelial lining of the tubule. B, stages in the de- velopment of spermatozoa. (After Parker and Parker.) the outer membrane. The follicle cells form a sort of wall around groups of cells from which the spermatozoa take their origin. The spermatozoa of the frog pass through the substance of the kidney into the ureter. In many species of frogs the free portion of the ureter is dilated to form a seminal recep- tacle in which the spermatozoa are stored against the time of their discharge from the body. The seminal receptacle is poorly developed in Rana pipiens and R. Catesbiana. In the European species R. fusca it becomes very large and divided into a number of compartments. Corresponding to the various stages in the development. 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
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Keywords: ., bookauthorholmessamueljsamuelja, bookcentury1900, bookdecade1910
