The evolution of man: a popular exposition of the principal points of human ontogeny and phylogene . Fig. 193.—Larva of Spotted Land-Newt (Salamandra maculata), fromthe ventral side. In the centre a yelk-sac yet protrudes from the external gills are prettily branched and tree-like. The two pairs oflimbs are yet very small. Fig. 194.—Larva of the Commop Grass-Frog (Rana tempn^-aria), a so-called tadpole: m, mouth; n, a pair of suction cups used in clinging to stones;d, skin-fold, which gives rise to the gill-roof; behind are the gill-openings,from which the gill branches protrude
The evolution of man: a popular exposition of the principal points of human ontogeny and phylogene . Fig. 193.—Larva of Spotted Land-Newt (Salamandra maculata), fromthe ventral side. In the centre a yelk-sac yet protrudes from the external gills are prettily branched and tree-like. The two pairs oflimbs are yet very small. Fig. 194.—Larva of the Commop Grass-Frog (Rana tempn^-aria), a so-called tadpole: m, mouth; n, a pair of suction cups used in clinging to stones;d, skin-fold, which gives rise to the gill-roof; behind are the gill-openings,from which the gill branches protrude ; s, tail-muscles; /, skin-fold of thetail, forming a float. irunk is produced into a long tail, which in form and struc-42 125 THE EVOLUTION OF MAN. ture resembles the tail of a Fish (s). At first it has nolimbs. Respiration is accomplished solely by gills, whichare at first external (Jc) and afterwards internal. Corre-spondingly, the heart is also of the same form as in theFishes, and consists of only two compartments—an auricle,which receives the venous blood of the body, and a ven-tric
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Keywords: ., bookcentury1800, booksubjectembryologyhu, booksubjecthumanbeings
