. A laboratory manual and text-book of embryology. Embryology. 220 UROGENITAL SYSTEM glands show two characters which mark them as testes: (i) The occurrence of branched anastomosing cords of cells, the testis cords; (2) the occurrence between epithelium and testis cords of a layer of tissue, the anlage of the tunica albuginea (Fig. 218). According to Felix, the testis cords are developed suddenly from the loose inner epithelial mass by a condensation of its cells. The cords converge and grow smaller towards the mesorchium, where there is formed the undivided epi- thelial anlage of the rete te
. A laboratory manual and text-book of embryology. Embryology. 220 UROGENITAL SYSTEM glands show two characters which mark them as testes: (i) The occurrence of branched anastomosing cords of cells, the testis cords; (2) the occurrence between epithelium and testis cords of a layer of tissue, the anlage of the tunica albuginea (Fig. 218). According to Felix, the testis cords are developed suddenly from the loose inner epithelial mass by a condensation of its cells. The cords converge and grow smaller towards the mesorchium, where there is formed the undivided epi- thelial anlage of the rete testis. Two or three layers of loosely arranged cells between the testis cords and the epithelium constitute the anlage of the tunica albuginea. According to Allen (Amer. Jour. Anat., vol. 3, 1904), the testis cords are formed as active ingrowths of cords of cells from the epithelium. Mesentery Mesonephrfc tubule. â 'if.â Mesotiephric duct %â Muellerian duct Intermediate cord Testis cord Epithelium â Tunica albuginea. Fig. 218.âTransverse section through the left testis and mesonephros of a 20 mm. embryo. X 250. The testis cords soon become rounded and are marked off by connective tissue sheaths from the intermediate cords, columns of undifferentiated tissue which lie between them (Fig. 219). Toward the rete testis the sheaths of the testis cords unite to form the anlage of the mediastinum testis. The testis cords are composed chiefly of indifferent cells with a few larger genital cells. The cells gradually arrange themselves radially about the inside of the connective tissue sheath as a many-layered epithelium in which during the seventh month a lumen appears. The lumina appear in the peripheral ends of the testis cords and ex- tending toward the rete testis meet lumina which have formed there. Thus the solid cords of both are converted into tubules. The distal portions of the testis. Please note that these images are extracted from scanned page images that may have been di
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