11 



the third or internal flap, were attached to a very short and thick 

 columna, arising from the septum ; below the left flap of the tricuspid 

 valve was a fleshy column, connecting the wall of the right ventricle 

 to the septum. 



At the origin of the aorta there was a single small curved bone. 



The arch of the aorta, after distributing the vessels to the heart, 

 gave oft', first, a large innominata, which subdivided into the right 

 vertebral artery, the right brachial artery, and the common trunk of 

 the two carotids ; secondly, the left brachial artery ; thirdly, the left 

 vertebral artery. The common trunk of the two carotids was remark- 

 able for its length. The cranial plexus of the internal carotid was 

 much less developed than in the ordinary grazing Ruminants. 



Nervous System. 



The brain of the GiraflPe closely resembled, in its general form, and 

 in the number, disposition, and depth of the convolutions, that of the 

 Deer : it was more depressed than in the Ox, and the cerebrum was 

 wholly anterior to the cerebellum. The anterior contour of the 

 cerebral hemispheres was somewhat truncated. 



The convolutions might be readily divided, as in other Ruminants, 

 into primary and secondary ; they averaged a breadth of three lines, 

 and were almost symmetrical in the two hemispheres. There was little 

 symmetry in the disposition of the primary convolutions in the cere- 

 bellum : the middle one on the upper surface, representing the su- 

 perior vermiform process, pursued a wavy course from side to side, 

 but the inferior vermiform process was straight, and very prominently 

 developed ; these, with the lateral convolutions of the cerebellum, 

 were subdivided by narrow and, for the most part, transverse folds. 

 Mr. Owen also enters into a detailed account of the internal struc- 

 ture of the brain ; and concludes his description of this organ by 

 giving the following admeasurements : Inches. Lines. 



Total length of the brain 5 3 



Vertical diameter of ditto 2 8 



Breadth of the cerebrum 4 3 



Length of the cerebellum 1 10 



Breadth of ditto 2 5 



Length oi pons varolii 1 



Breadth of ditto 1 6 



Weight of the brain, 14oz. avoirdupois. 

 The olfactory nerves were large, as in most Ruminantia, and ter- 

 minated in expanded bulbs, in length 1^ inch, in breadth 1 inch : 

 these were lodged in special compartments of the cranial cavity. The 

 optic nerves and ninth pair were relatively larger than in the Deer. 

 The other cerebral nerves presented no peculiarity. 



The spinal chord had a close investment of dura mater, and was 

 remarkable for the great length of its cervical portion, which, in the 

 Giraff'e dissected at the Zoological Gardens, measured upwards of 

 three feet, the entire length of the animal from the muzzle to the 

 vent being eight feet. Mr. Owen here particularly describes the ap- 

 pearance in the origins of the cervical nerves depending upon the 



