This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1905 Excerpt: ...from the truncus. Essentially this same arrangement is retained through a late stage in development, at least for nine weeks after hatching. In the adult, however, the lateral ventral aortse like the truncus, have disappeared and the afferent branchial arteries seem to arise directly from the conus (Fio. 50). The heart ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1905 Excerpt: ...from the truncus. Essentially this same arrangement is retained through a late stage in development, at least for nine weeks after hatching. In the adult, however, the lateral ventral aortse like the truncus, have disappeared and the afferent branchial arteries seem to arise directly from the conus (Fio. 50). The heart lies entirely posterior to the branchial region so that these arteries are all given off anteriorly. The early condition of the truncus of Ceratodus is precisely that of Sana according to Marshall and Bles ('90) who describe it (p. 199) as dividing at once "into right and left branches which run directly outwards at right angles to the axis of the body, and just below the floor of the pharynx. Each division of the truncus is flattened dorso-ventrally, and ends blindly, its extremity usually showing a more or less marked tendency to divide into two or three lobes." Later the truncus widens considerably, and from its extremities are formed the afferent branchial diverticula. The truncus of the Anamnia in general, of course, develops as a wide shallow channel, but it is significant that the truncus of Ceratodiis during its early formation is so closely similar to that of Rana or of Salamandra (Greil, '03). 5. General Considerations Concerning The Development Of The Vessels Of The Branchial Arches. Formation of the Aortic,4rcA.--The four pairs of branchial arteries of Ceratodus are all formed of similar elements and in the same manner. These elements are the following. (1) A diverticulum extending from the lateral dorsal aorta downward a short distance into the branchial arch; this is the efferent diverticulum (e.d., Fig. 53, Pl. XIII). The lateral dorsal aorta; are formed some time before any other vessels in this region so that this d...
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Add this copy of The Development of the Vascular and Respiratory Systems to cart. $41.36, good condition, Sold by Bonita rated 4.0 out of 5 stars, ships from Newport Coast, CA, UNITED STATES, published 2012 by Nabu Press.