Quain's elements of anatomy . the origin of the thymus has beenconfirmed by the observations of Stieda in the pig and sheep, in whichhe found the thymus to arise as a paired outgrowth from the remnantsof two visceral clefts ; and he and Wolfler attribute a similar mode oforigin to the thyroid body. (273 and 274.) V, DEYELOPMENT OF THE TRmARY AND GENERATIYE OEGANS. I. GENERAL VIEW. The development of the permanent urinary and generative organs haslong been known to be intimately associated with that of the embryonicglandular organs named the jDrimordial kidneys, or after their discoverer,C. F.
Quain's elements of anatomy . the origin of the thymus has beenconfirmed by the observations of Stieda in the pig and sheep, in whichhe found the thymus to arise as a paired outgrowth from the remnantsof two visceral clefts ; and he and Wolfler attribute a similar mode oforigin to the thyroid body. (273 and 274.) V, DEYELOPMENT OF THE TRmARY AND GENERATIYE OEGANS. I. GENERAL VIEW. The development of the permanent urinary and generative organs haslong been known to be intimately associated with that of the embryonicglandular organs named the jDrimordial kidneys, or after their discoverer,C. F. Wolff, the Wolifian Bodies. This association was fiist ascertained 890 UEINART AND GENERATIVE ORGANS. by H. Eathke, Oken, and Job. Mliller more than fifty years ago, and thefuller knowledge of its nature has been illustrated by numerous embry-ologists in investigations of more recent date (Bornhaupt, Kobelt,KoUiker, Waldeyer, Semper, Balfour and others). Wol£ Bodies and Segmental Organs.^—According to the two Fig. Fig. 796.—Diagrammatic orrTLiNE OF THE WOLFFIAN BODIES INTHEIR RELATIONS TO THERUDIMENTS OF THE REPRODUC-TIVE ORGANS. (A. T. ) ot, seat of origin of the ovariesor testes ; W, Wolffian bodies;^w.^y, Wolffian ducts; mm, Miillerianducts ; gc, genital cord ; iig, sinusurogenitalis ; i, intestine , d,cloaca. last named observers, theWolffian bodies are the rep-resentatives in a certainstage of their developmentof a set of tubular glands orexcietory organs existing inall vertebrates and in a cer-tain number of invertebrateanimals, especially annelida,to which the general nameof segmental organs may be given, from their relations to the metameriosomites of the body. It was first shown by Eathke in 1826 that the Wolffian bodies ofall vertebrates consist of glandular tubes with which are combinedvascular glomeruli of the same general nature as those of the adultkidney; and recent researches have further shown that an essentialstructural character of the bodies i
Size: 1337px × 1868px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., boo, bookcentury1800, booksubjectanatomy, booksubjecthumananatomy
