Archive image from page 73 of Cunningham's Text-book of anatomy (1914). Cunningham's Text-book of anatomy cunninghamstextb00cunn Year: 1914 ( Fig. 51.—View of Dorsal Aspect of a Human Embryo—1'38 mm. Long, before the appearance of the limbs. (From Keibel and Elze, Normaltafeln.) Fig. 52.—Dorsal lateral View of a Human Embryo — 24 mm. Long. The Wolffian ridge is seen at the lateral border of the meso- dermal somites. (Keibel and Elze, Normaltafeln.) bud is the rudiment of the distal segment of the future limb, the hand in the case of the fore-limb, and the foot in the case of the hind-limb. As
Archive image from page 73 of Cunningham's Text-book of anatomy (1914). Cunningham's Text-book of anatomy cunninghamstextb00cunn Year: 1914 ( Fig. 51.—View of Dorsal Aspect of a Human Embryo—1'38 mm. Long, before the appearance of the limbs. (From Keibel and Elze, Normaltafeln.) Fig. 52.—Dorsal lateral View of a Human Embryo — 24 mm. Long. The Wolffian ridge is seen at the lateral border of the meso- dermal somites. (Keibel and Elze, Normaltafeln.) bud is the rudiment of the distal segment of the future limb, the hand in the case of the fore-limb, and the foot in the case of the hind-limb. As the limb-rudiment increases in length the more proximal segments of the limb are differentiated, the forearm and arm in the case of the fore-hmb, and the leg and the thigh in the case of the hind-limb. At the same time the limbs are folded ven- trally, so that their original ventral surfaces become medial and their original dorsal surfaces lateral, and the convexities of the elbows and knees are directed laterally. At a later period, on account of a rotation which takes place in opposite directions in the fore- as contrasted with the hind- Hmbs, the convexity of the elbow is turned towards the caudal end of the body and that of the knee towards the cephalic end. It is only at much later periods of de- velopment, as the erect posture is assumed, that the convexity of the Fig. View of a Human Embkyo-2'1 mm. greatest elbow is directed dorsally and the length, showing limb buds projecting from the Wolffian ridge. •. n .-, n J , n (Keibel and Elze, Normaltafeln.) convexity of the knee ventrally. The terminal or distal seg- ment of each limb is, at first, a flat plate with a rounded margin, but it soon differenti- ates into a proximal or basal part and a more flattened marginal portion. It is along the line where these two parts are continuous that the rudiments of the digits appear. They become evident as small elevations on the dorsal surface of the limb bud
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Keywords: 1910, 1914, anatomy, archive, book, bookauthor, bookdecade, bookpublisher, booksubject, bookyear, cunningham_d_j_daniel_john_1850_1909, drawing, historical, history, illustration, image, new_york_w_wood, page, picture, print, reference, robinson_arthur_b_1862_ed, vintage
