The evolution of man: a popular exposition of the principal points of human ontogeny and phylogenyFrom the German of Ernst Haeckel . nand Wolffian ducts, their laterliistory is clear and all Double-nostrilled () and Jaw-mouthed(Gnathostomi) animals, fromPrimitive Fishes up to Man,the Wolffian duct becomes theseed-duct, and the Miillerianduct, the oviduct. In eachsex only one of these is per- FiGS. 322,323.—Urinary and sexualorgans of an Amphibian (Water-Nowt,or Triton). Fig. 322 (A), female;Fig. 323 (jB) , male : r, primitiye kid-ney ; ov, ovary; od, egg-dnct andRathkes
The evolution of man: a popular exposition of the principal points of human ontogeny and phylogenyFrom the German of Ernst Haeckel . nand Wolffian ducts, their laterliistory is clear and all Double-nostrilled () and Jaw-mouthed(Gnathostomi) animals, fromPrimitive Fishes up to Man,the Wolffian duct becomes theseed-duct, and the Miillerianduct, the oviduct. In eachsex only one of these is per- FiGS. 322,323.—Urinary and sexualorgans of an Amphibian (Water-Nowt,or Triton). Fig. 322 (A), female;Fig. 323 (jB) , male : r, primitiye kid-ney ; ov, ovary; od, egg-dnct andRathkes duct, both formed from theMiillerian duct; w, primitive urinaryduct—acting, in man, also as seed-duct (ve)—opening below into Wolffsduct (u) ; ms, ovary-mesentery {mes-ovarium). (After Gegenbaur.) sistent; the other entirely disappears, or leaves only aremnant as a rudimentary organ. In the male sex, mwhich the two Wolffian ducts become sperm-ducts, certainrudiments of the Miillerian duct are often found, whichwe will call Rathkes canals (Fig. 823, c). In the femalesex, where, on the contrary, the two Miillerian ducts60. 4i6 THE EVOLUTION OF MAN. become oviducts, traces of the WolfRan ducts remain, andare known as Gartners canals. ^^/MimMMMk
Size: 1046px × 2389px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, booksubjectembryology, booksubjectembryologyhum
