. Journal of anatomy. he hypophysis. Theanterior extremity is pressed against the posterior wall of Rathkes pouch,which is thereby indented slightly in the middle line. A rounded depression in the diencephalic floor represents the primitiveinfundibular recess, but no infundibular process is yet difterentiated. The notochord in this embryo reaches actually to the level of theposterior wall of Seessels pocket, but is not in actual contact therewith. Stage III. 9 mm.—The hypophysis has increased considerably 216 Dr Katharine M. Parker in size, but is still widely open anteriorly and consists
. Journal of anatomy. he hypophysis. Theanterior extremity is pressed against the posterior wall of Rathkes pouch,which is thereby indented slightly in the middle line. A rounded depression in the diencephalic floor represents the primitiveinfundibular recess, but no infundibular process is yet difterentiated. The notochord in this embryo reaches actually to the level of theposterior wall of Seessels pocket, but is not in actual contact therewith. Stage III. 9 mm.—The hypophysis has increased considerably 216 Dr Katharine M. Parker in size, but is still widely open anteriorly and consists of proximal anddistal lobes. A definite infundibular process is present in the form of a short conicaloutgrowth of the diencephalic floor (fig. 84, ). This is in intimatecontact with both Rathkes pouch and the pre-oral gut (vide infra). Remnants of the oral plate are present in the form of a solid, knob-likemass of tissue lying outside the pouch and a small portion lying free inthe lumen of Rathkes pouch. Fig. 32.—Stage II. Phascolardos cinercus. Transversesection through Seessels pocket. SI. 5-1-2. Dien., diencephalic floor; Hyp., posterior wall of one of lateralcaudal lobes of the hypophysis; , oral plate; ,Seessels pocket. Seessels pouch has lost its opening into the gut and simply forms aclosed, hollow vesicle, in intimate contact with Rathkes pouch, but havingno communication with it. It is elongated in the antero-posteriordirection, and is divided as before into two lobes, whose cavities are nowcompletely separate from each other. Its walls consist, as before, ofregular columnar epithelial cells, and resemble those of the hypophj^ closely that in the posterior region, where Rathkes pouch is bifid andSeessels pocket lies between the two halves, there appear to be threeprecisely similar lobes of the hypophysis (fig, 34), The Development of the Hypophysis Cerebri, etc., in Marsupialia 217 Anterior to the point of bifuication of Rathkes pouch, th
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectanatomy, bookyear1867
