File:Lewis1903 plate03.jpg

Plate III

Pig Embryo of 12.0 mm. Reconstruction from transverse sections, Series 5 and 518.

For the most part the organs represented are in or near the mediae plane. The drawing illustrates especially the alimentary tract, the arterial system, and the heart. A. bas. Basilar artery. A. can. Caudal artery. AU, Allantois. Ao, Median dorsal aorta. An. d, Ao. D, Right dorsal aorta. A. s. Subclavian artery. Am, Left auricle. A. um, Umbilical artery. A. ti,. Vitelline artery (Omphalo-mesenteric). c, Coeliac axis. car. e. External carotid artery, car. i. Internal carotid artery. Cbl, Cerebellum, cl. Cloaca, cl. mem, Cloacal membrane, d. Left duct of Cuvier. Dion, Diencephalon. D. V, Ductus venosus Arantii. ep, Epithelial plug in the rectum. Epgl, Epiglottis. f, interventricular foramen opening into the space a, b, c, of PL 4. Fni, Foramen of Monro, f, o. Foramen ovale, g, Gall-bladder. In, Entodermal wall of the intestine, is, An intersegmental artery. Ki, Renal pelvis. Lar, Larynx, Li, Liver. Lu, Lung. M. b. Mid-brain. Md. ob. Medulla oblangata. N, A spinal nerve. Neu, Neuromeres. Oe, Oesophagus, op. Optic stalk. P. A, Pulmonary artery. Pan, Dorsal anlage of the pancreas, behind the duct of which is the ventral anlarge. P, c. Peri-cardial cavity, P. V, Pulmonary vein. Sp. c, Spinal cord. St, Stomach. /, Posterior portion of the tongue. T. /, Tuberciilum impar. Ti'u, Trachea. Um. d, Eight iimbilical vein. Vcn, Left ventricle. T. mes, Superior mesenteric vein. V. port. Portal vein. Y. in. Vitelline vein (Omphalo-mesenteric. W. D, Wolthan duct, x. Anastomosis between the right and left cardinal systems. Yk, Yolk sac. Yfc. s, Yolk stalk. x 13.5 diams.