An introduction to the study of embryology / by Alfred C. Haddon.

  • Haddon, Alfred C. (Alfred Cort), 1855-1940.
Date:
1887
Catalogue details

Licence: Public Domain Mark

Credit: An introduction to the study of embryology / by Alfred C. Haddon. Source: Wellcome Collection.

Provider: This material has been provided by University of Bristol Library. The original may be consulted at University of Bristol Library.

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    blood from behind is returned to the heart by the subintestinal vein, and not by the vitelline veins (Vm). The first or mandibular arterial arch is represented by a small vessel which arises from the branchial vein of the hyoid arch, and supplies the rudimentary gill (pseudobranch) of the spiracle. In other Fish this artery of the first arch disappears. The second or hyoid arterial arch is functional throughout life in Elasmobranchs ; usually it remains as a small vessel which goes to the pseudobranch of the hyoid. The artery is said to persist in Protopterus amongst the Dipnoi. The air-bladder is supplied with arterial blood from the caeliac artery or direct from the aorta, except in some Ganoids (Polypterus Fig. 172.—Venous Circttlation IN Mammalian Embryo. [From Landois and Stirling.] I. Early arrangement of veins. II. Final disposition. Ad. right innominate vein; As. left innominate vein; Az. azygos vein; 6. subclavian veins; Ci. vena cava inferior; ci. posterior vertebral veins; Cs. vena cava inferior; cs. anterior cardinal vein; DC. ductus Cuvieri (superior vense oavse); /. external iliac vein; h. hypogastric vein; Hz. hemiazygos vein; le. ex- ternal jugular vein; Ji. internal jugular vein; am, vitelline or om- phalo-mesenteric vein; U. umbilical or allantoic vein; V. ventricle ; Vc. vena cava inferior. and Amia) and Dipnoids, where the last branchial arch sends an artery direct to the air-bladder. In Amphibia the first aortic arch (mandibular) is never devel- oped, and the- second (hyoid) arises later than the succeeding arches; it never unites dorsally with the latter, and only gives rise in part to the lingual artery. Of the four branchial aortic arches present in larval Amphibia, only the second, in the Anura, retains its connection with the dorsal aorta. The first becomes the carotid arch, and gives rise to the carotids; the second forms the systemic arch; the third is rudimentary or absent (Anura) in the adult, while the fourth or pulmonary supplies the lungs. A narrow anastomosis or ductus