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ALYTES

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Originally appearing in Volume V01, Page 776 of the 1911 Encyclopedia Britannica.
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ALYTES , the See also:

midwife See also:toad, first discovered by P. Demours in 1741, on the border of a small See also:pond in the Jardin See also:des Plantes, in the very See also:act of parturition which has rendered it famous, and described as See also:Petit crapaud male accoucheur de sa femelle. Alytes obstetricans is of See also:special See also:interest as the first known example of paternal solicitude in Batrachians, and although many no less wonderful cases of See also:nursing See also:instinct have since been revealed to us, it remains the only one among See also:European forms. Alytes obstetricans is a small toad-like Batrachian, two inches in length, of dull greyish coloration, plump See also:form with warty skin and large eyes with See also:vertical pupils. Although toad-like it is not really related to the toads proper, but belongs to the See also:family Discoglossidae, characterized by a circular, adherent See also:tongue, See also:teeth in the upper See also:jaw and on the See also:palate, See also:short but distinct ribs on the anterior vertebrae, and See also:convex-See also:concave vertebrae. It inhabits See also:France, See also:Belgium, See also:Switzerland, Western See also:Germany (See also:east-wards to the See also:Weser), See also:Spain and See also:Portugal. A second See also:species, A. cisternasii, occurs in Spain and Portugal. A lytes is nocturnal and slow in its movements. It is thoroughly terrestrial, selecting for its See also:retreat in the daytime holes made by small mammals, or interstices between stones. Towards evening it reveals its presence by a clear whistling See also:note, which has often been compared to the See also:sound of a little See also:bell, or to a See also:chime when produced by numerous individuals. The breeding See also:season lasts throughout See also:spring and summer, and the See also:female is able to spawn two, three or even four times in the See also:year. Pairing and oviposition take See also:place on See also:land; the male seizes the female See also:round the See also:waist.

The eggs are large and yellow, and produced in two See also:

rosary-like strings, as if strung together by elastic filaments continuous with the gelatinous capsules. After impregnation, the male twists them round his legs and returns to his usual retreat, going about at See also:night in See also:order to feed himself and to keep up the moisture'of the eggs, even resorting to a short See also:immersion in the See also:water during exceptionally dry nights. The development of the embryo within the See also:egg takes about three See also:weeks. When the See also:time foredosion has come, the male enters the water with his See also:burden; the larvae, in the full See also:tadpole See also:condition, measuring 14 to 17 millimetres, bite their way through their tough envelope, which is not abandoned by the See also:father until all the See also:young are liberated, and See also:complete in the See also:ordinary way their See also:metamorphosis. The tadpoles grow to a large See also:size considering that of the adult, the See also:body equalling in size a See also:sparrow's or even a small See also:pigeon's egg, and they often remain more than a year in that condition. See A. de 1'Isle, " Memoire sur See also:les mceurs et l'accouchement de 1'Alytes obstetricans," See also:Ann. Sci. Nat. (6) iii. 1876; G. A. Boulenger.

Tailless Batrachians of See also:

Europe (See also:Ray Society, 1897). (G. A.

End of Article: ALYTES

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