. Text-book of embryology. Embryology. VIII DEVELOPMENTAL ADAPTATIONS 461 medusa iheringii (von Ihering, 1886), Hyla nebulosa (Goeldi, 1895), JRhacuphorus reinioardtii (Siedlecki, 1909). In the last mentioned the eggs are deposited in a mass of foam enclosed in one or several leaves (Fig. 210). At the appropriate time the central portion of the mass liquefies and the colourless tadpoles make their way into this central fluid — the superficial layer of the mass being hard and dry. Eventually the lower part of the mass softens and the liquid containing the tadpoles trickles out on to the ground
. Text-book of embryology. Embryology. VIII DEVELOPMENTAL ADAPTATIONS 461 medusa iheringii (von Ihering, 1886), Hyla nebulosa (Goeldi, 1895), JRhacuphorus reinioardtii (Siedlecki, 1909). In the last mentioned the eggs are deposited in a mass of foam enclosed in one or several leaves (Fig. 210). At the appropriate time the central portion of the mass liquefies and the colourless tadpoles make their way into this central fluid — the superficial layer of the mass being hard and dry. Eventually the lower part of the mass softens and the liquid containing the tadpoles trickles out on to the ground where the larvae are able to continue their development in the smallest puddles. In the second type of such adaptations the eggs or young are carried about, away from the water, by one of the parents. In the simplest of such cases no structural modification of the parent's body is involved. Thus in Alytes obstetricans the male draws the strings of eggs out of the cloacal aperture of the female and loops them round his thighs—the portion of oviducal secretion lying between successive eggs becoming highly elastic and gripping the thighs tightly. Oviposition takes place on land and the male pays only occasional visits to the water. When one of these happens at the appropriate period the young hatch in the form of tadpoles while the male parent resumes his terrestrial habits. In a number of cases the transport of the young by the parent takes place at a later period, when the tadpole stage has been reached, the larvae adhering bo the back of the male parent and so being transported from one pool to another (Fig. 211, A). This habit occurs in various species of Dendrobates and Phyllo- bates (Brandes u. Schoenichen, 1901). In the most interesting cases however the transport of the eggs or young by the parent is associated with the making use of some particular structural feature of the latter—either permanent or specially developed for this purpose. In Rhacophorus reticulatus (
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