. Zoology : for students and general readers . Zoology. METAMOBPHOSIS OF BATRACHIANS. 47: size. The next important change is the growtli of the front legs and the paitial disappearance of the tail (C), while very small toads {D and E), during midsummer, may be found on the edges of the pools in which some of the nearly tailless tad- poles may be seen swimming about. It is three years before the Amphibia are capable of breeding. In the newts {Tri- ton) the gills are in three pairs, larger and more complex than in the frog ; the fore limbs are the first to grow out, and the gills persist long af
. Zoology : for students and general readers . Zoology. METAMOBPHOSIS OF BATRACHIANS. 47: size. The next important change is the growtli of the front legs and the paitial disappearance of the tail (C), while very small toads {D and E), during midsummer, may be found on the edges of the pools in which some of the nearly tailless tad- poles may be seen swimming about. It is three years before the Amphibia are capable of breeding. In the newts {Tri- ton) the gills are in three pairs, larger and more complex than in the frog ; the fore limbs are the first to grow out, and the gills persist long after the hind limbs are developed. In the newts we have the larval state of the toads and frogs persistent; thus the successive steps in the development of the individual frog is an epitome of the evolution of the typical forms of the class to which it Pig. 4&4.—Metamorphosis of tlie Toad.—After Owen ; from Tenney's Zoology. In certain Batrachians as the Alpine salamander, the Su- rinam toad {Pipa) and the Hylodes of Guadaloupe in the West Indies, the metamorphosis is sujopressed, development being direct; though the young have gills, they do not lead an aquatic life. In the axolotl there is a premature devel- opment of the reproductive organs, the larvae as well as the adults laying fertile eggs. The Batrachians are inhabitants of the warmer and tem- perate zones. Progs extend into the arctic circle. The Amhlystoma mavortium breeds at an altitude of about 8000 feet in the Rocky Mountains. Eana septentrionalis Baird extends to Okak, Northern Labrador, where the climate is as extreme as that of Southern Greenland ; frogs have also been. 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 Packard, A. S. (Alpheus Spring), 1839-1905. New York : Henry Holt
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectzoology, bookyear1879
