The development of the human body; a manual of human embryology . 324 THE DEVELOPMENT OF THE HUMAN BODY. pace, however, with that of the portion nearest the intes-tine, but it becomes gradually more and more distin-guished and gives rise to the vermiform appendix. Atbirth the original conical form of the entire outgrowthis still distinguishable, though it is more properly de-scribed as funnel-shaped, but later the proximal part, con-tinuing to increase in diameter at the same rate as thecolon, becomes sharply separated from the appendix,forming the caecum of adult Fig. 173.—Reconstru
The development of the human body; a manual of human embryology . 324 THE DEVELOPMENT OF THE HUMAN BODY. pace, however, with that of the portion nearest the intes-tine, but it becomes gradually more and more distin-guished and gives rise to the vermiform appendix. Atbirth the original conical form of the entire outgrowthis still distinguishable, though it is more properly de-scribed as funnel-shaped, but later the proximal part, con-tinuing to increase in diameter at the same rate as thecolon, becomes sharply separated from the appendix,forming the caecum of adult Fig. 173.—Reconstruction of a Portion op the Intestine of anEmbryo of 28 mm., showing the Longitudinal Folds from whichthe Villi are Formed.—(Berry.) Up to the time when the embryo has reached a length of14 mm., the inner surface of the intestine is quite smooth,but when a length of 19 mm. has been reached, the mu-cous membrane of the upper portion becomes thrown intolongitudinal folds, and later these make their appearancethroughout its entire length (Fig. 173). Later, in em-bryos of 60 mm., these folds break up into numbers ofconical processes, the villi, which increase in number THE LIVER. 325 with the development of the intestine, the new villi ap-pearing in the intervals between those already present. A remarkable phenomenon has recently been described asoccurring in the duodenum of embryos of about mm. Itconsists in a rapid growth in the thickness of the mucous mem-brane, whereby the lumen of the intestine immediately belowthe opening of the hepatic and pancreatic ducts
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectembryol, bookyear1902
