The development of the human body; a manual of human embryology . opographic relation, there being no develop-mental relation between the two structures. Their development has been very variously the Mammalia they arise by the proliferation of cellssituated at the extremities of invaginations of the coelomicepithelium into the Wolffian ridge (Fig. 210), the groups THE SUPRARENAL BODIES. 391 of cells so formed from the several invaginations later unit-ing together to form a relatively large organ. The invagi-nations resemble closely in appearance and position thetubules and funnels
The development of the human body; a manual of human embryology . opographic relation, there being no develop-mental relation between the two structures. Their development has been very variously the Mammalia they arise by the proliferation of cellssituated at the extremities of invaginations of the coelomicepithelium into the Wolffian ridge (Fig. 210), the groups THE SUPRARENAL BODIES. 391 of cells so formed from the several invaginations later unit-ing together to form a relatively large organ. The invagi-nations resemble closely in appearance and position thetubules and funnels of the pronephros (see p. 361), andthey have recently (Aichel) been regarded as representingfunnels belonging to the mesonephros. One of the char-acteristics of the mammalian mesonephros is that it pos-sesses no nephrostomes, but in the lower vertebrates suchstructures do occur, and it is possible that the invagina-tions of the coelomic epithelium which give rise to thesuprarenals may be representatives of certain meso- wc «**».>*.> ^sm* l\ J =.--=.**.. ss*5*X7\ Jo Fig. 210.—Section through a Portion op the Wolffian Ridge of a Rabbit Embryo of mm. Ao, Aorta; ns, nephrostome; Sr, suprarenal body; vc, cardinal vein; wc, tubule of Wolffian body; ied, Wolffian duct.—{Aichel.) nephric funnels which have failed to unite with the tu-bules and have undergone a secondary transformation. That the suprarenals are primarily connected with themesonephros becomes exceedingly probable from the factthat similar structures, known as the accessory suprarenalsof Marchand, not infrequently occur between the layersof the broad ligament of the female and in the vicinity ofthe epididymis in the male and are developed from thedegenerating tubules of the epoophoron or paroophoron,and presumably from the corresponding structures in themale. 392 THE DEVELOPMENT OF THE HUMAN BODY. It is doubtful, however, if the entire mass of the supra-renal organs is derived from the constituents furnis
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectembryol, bookyear1902
