The evolution of man : a popular exposition of the principal points of human ontogeny and phylogeny . ls, and changed into a form closely allied to that ofthe Salamander (Amblystoma, Fig. 2). In this state theybecame sexually This phenomenon, which atfirst excited a lively interest, has since been repeatedlyobserved with care. Zoologists regarded the fact as some-thing peculiarly wonderful, though each spring everycommon Frog and Salamander passes through the samemodification. In these animals we can in the same wavfollow each step in the significant metamorphosis of theaquatic and
The evolution of man : a popular exposition of the principal points of human ontogeny and phylogeny . ls, and changed into a form closely allied to that ofthe Salamander (Amblystoma, Fig. 2). In this state theybecame sexually This phenomenon, which atfirst excited a lively interest, has since been repeatedlyobserved with care. Zoologists regarded the fact as some-thing peculiarly wonderful, though each spring everycommon Frog and Salamander passes through the samemodification. In these animals we can in the same wavfollow each step in the significant metamorphosis of theaquatic and gill-respiring animal into the terrestrial andlung-respiring animal. That which thus takes place in theindividual during germ-evolution, took place in the sameway in the whole class during the course of its tribalhistory. The metamorphosis which takes place in the third order haeckels evolution of man. PLATE XIT. w:m i^.OT %l 7Jw?. ^.lO1 ti$ a#H K? &<; #1 j^i; ml lj;W. i, ,\J_ ? .11IP A, -i; it ,;4« Sp He. I K-V^ ifi; a |N^ Grafocfus Ibrsteri EVOLUTION OF MAN. PLATE . lull Fig. i. Siredon pisciformis. Fig. 2. Salamandra maculata. TAILED BATRACHIANS AND FROG BATRACHIANS. 131 of Amphibia, the Frog Batrachians (Batrachia, or Anura),is yet more complete than in the Salamanders. To thesebelong all the various kinds of Toads, Water-frogs, Tree-frogs, etc. In the course of transformation these lose notonly the gills, but also the tail, which drops off in somecases earlier, in others later. In this respect the variousspecies differ somewhat from one another. In most FrogBatrachians the larv?e drop the tail very early, and thetail-less frog-like form subsequently grows considerablylarger. Other species, on the contrary, as, for instance, thePseudesparadoxus of Brazil, as also an European Toad (Pelo-batesfuscus) remain for a very long time in the fish form,and retain a lengthy tail till they have almost attainedtheir full size; hence, after their metamorpho
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Keywords: ., book, bookcentury1800, bookdecade1870, booksubjectembryologyhuman
