. Outlines of zoology. Zoology. ORGANS OF CHELONIA. 565 Some Peculiarities in the Organs of Chelonia. The brain of the adult shows a slight curvature in all higher animals ex- cept serpents, there aie twelve cranial nerves, for, in addition to the usual ten, a spinal accessory to cervical muscles, and a hypoglossal to the tongue, are ranked as the eleventh and twelfth. The gullet of the turtle shows in great develop- ment what is hinted at in others, long horny papillse pointing downwards ; it is probable that these help to tear up the food (sea- weed in the case of the turtle). There are usua
. Outlines of zoology. Zoology. ORGANS OF CHELONIA. 565 Some Peculiarities in the Organs of Chelonia. The brain of the adult shows a slight curvature in all higher animals ex- cept serpents, there aie twelve cranial nerves, for, in addition to the usual ten, a spinal accessory to cervical muscles, and a hypoglossal to the tongue, are ranked as the eleventh and twelfth. The gullet of the turtle shows in great develop- ment what is hinted at in others, long horny papillse pointing downwards ; it is probable that these help to tear up the food (sea- weed in the case of the turtle). There are usually blind pockets or anal bursse connected with the cloaca. The heart is three-cham- bered, but an incomplete septum divides the ven- tricle into a right portion, from which the pulmonary arteries and the left aortic arch arise, and a left por- tion, from which the right aortic arch issues. From In Chelonians and. Fig. 243. âInternal view of skeleton of turtle. â¢âFrom Edinburgh Museum of Science and Art. H., Humerus; Sc, scapula, running dorsally; c, coracoid ; epicoracoid; , precoracoid ; P., pubis; 1/., ilium, running dorsally; Is., ischium; J*., femur. the right aortic arch, which contains more pure blood than the left, the carotid and subclavian arteries are given off. The left aortic arch gives off the cceliac artery before it unites with the right. Unlike other Reptiles, the Chelon- ians are said to have no renal-portal system. The lungs are attached to the dorsal wall of the thorax, and have only a ventral investment of peri- Fig. of Cheloman toneum each is div;ded int0 a series Huxley. of compartments into which branches , Right half of ventricle; S., 0f the bronchus open. There is a septum ; left half of ventricle ; t- , ,. wââââiââ. n j;ââi,..ââm » *â .£., right aiiicle;/.«., left auricle! slight muscular diaphragm. , left aortic arch; , right In the males, the kidney, the epi- aortic
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Keywords: ., bookauthorth, bookcentury1800, bookdecade1890, booksubjectzoology
