. The Cambridge natural history. Zoology. 5! ANURA Strongly dilated discs on the fingers and toes, Rana loMU- hmdl, Jl. nutatrix, and J,', cavikjmpanum of Borneo, B. jerboa of Java (this larva was orighially described and figured as that of FJutcophoriis reimanrlti), and 1!. afghana of the Himalayan system. These tadpoles, at least those of R. jerboa, are further remarkable for ha\'ing the " spiracular " opening very far back on the left side, nearer to the base of the tail than to the snout, so as to be well out of the way when the creature has attached itself by the adhesive d
. The Cambridge natural history. Zoology. 5! ANURA Strongly dilated discs on the fingers and toes, Rana loMU- hmdl, Jl. nutatrix, and J,', cavikjmpanum of Borneo, B. jerboa of Java (this larva was orighially described and figured as that of FJutcophoriis reimanrlti), and 1!. afghana of the Himalayan system. These tadpoles, at least those of R. jerboa, are further remarkable for ha\'ing the " spiracular " opening very far back on the left side, nearer to the base of the tail than to the snout, so as to be well out of the way when the creature has attached itself by the adhesive disc. The mouth of the tadpoles of Anura is furnished with horny armaments, substitutes for teeth. Their development and that of the mouth in general has been well described by Gutzeit.^ In the young larvae of Rana tniipyrarin, one or two days after hatching, a shallow groove appears above the conspicuous pair of adhesive organs. The groove becomes rhombic in outline, and when the mouth has been formed in its centre, the jaws appear in the median corners of the rhombus. The epidermis then rises like a circular wall around the jaws, and Fig. 10.^1, Front view of the mouth of a tad- divides into an upper and pole of Puiim , showing tlie trans- i. n rows of tiny horny teeth; 2, three lower lip ; turroWS appear successive horny teeth, much magnified. (After ^^^ them and between Gntzeit.) .' . these various papillae and comb-like transverse plates of teeth. The papillae are pos- sibly tactile organs, but although nerves enter them, nerve- endings of a sensory nature have not yet been discovered. On the fourth day the jaws become black, by the tenth day horny teeth have appeared upon all the plates of the mouth- armatin-e, and on the seventeenth day the mouth-apparatus has reached the configuration typical of the tadpole, which is now about 14 mm. long. The number of horny teeth in R. terwporaria amounts to about 640. These teeth are not euticular products, but (Mjrn
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
