516 



RUMINANTIA. 



shallow. In the Camel there is an additional 

 process at the parotid border (w, Jig. 334.), 

 analogous to the similar but more marked 

 apophysis in Carnivora. 



Cranial peculiarities. Under this head we 

 proceed to notice certain arrangements re- 

 quiring further attention, and in the first 

 place the remarkable sinuses which exist in 

 the skull of the Giraffe. Though these be 

 nothing more than an extension of the 



Fig. 



ordinary frontal, ethmoidal and sphenoidal 

 cells, yet their significance is not the less 

 apparent or important when considered in a 

 physiological or teleological point of view. 



It has been considered necessary to pre- 

 serve the cranium of the Giraffe at present in 

 our possession entire ; consequently, we are 

 unable to offer any account of these sinuses 

 from personal examination, which is the less 

 to be regretted, as Prof. Owen has placed 



338. 



Sectional mew of the cranium of the Giraffe. (From Owen.) 



on record the following description of this 

 structure * ; " The part of the skull to 

 which the elastic ligament is attached is 

 raised considerably above the roof of the 

 cranial cavity by the extension backwards of 

 large sinuses, or air-cells, as far as the occiput. 

 The sinuses commence above the middle of 

 the nasal cavity, and increase in depth and 

 width to beneath the base of the horns, where 

 their vertical extent equals that of the cere- 

 bral cavity itself. The exterior table of the 

 skull, thus widely separated from the vitreous 

 table, is supported by stout bony partitions, 

 extended chiefly in the transverse direction, 

 and with an oblique and wavy course. Two 

 of the most remarkable of these bony walls 

 are placed at the front and back part of the 

 base of the horns, intercepting a large sinus 

 immediately over the middle of the cranial 

 cavity, and from a third and larger one be- 

 hind. The sphenoidal sinuses are of a large 

 size." 



Slight differences in the development of 

 the cranium are found in Giraffes inhabiting 

 respectively the more northern or southern 

 regions of Africa, these peculiarities having 

 especial relation to the position and approxi- 

 mation of the horns. In the Abyssinian 

 specimen (about two years old) dissected by 

 us, several particulars were noted, a few of 

 which are here selected f : 



* Memoir on the Anatomy of the Nubian Giraffe, 

 .ZooL Trans, vol. ii. p. 235. 



f Dr. Cobbold, On the Anatomy of the Giraffe, 

 Annals of Nat. Hist, for June, 1854. 



Inches 

 19 



Length of cranium - 



Breadth between orbits - 8 



Incisive angle to central eminence - - 11J 



Length of horns _ - - 5i 



Distance between horns at the base - - 0$ 



Depth of orbit 



Diameter of orbital ring - 2A 



Breadth of occipital condyles - 3| 



Vertical depth of each condyle - 2^ 



Length of lower jaw - 15 



In this list will be remarked the extreme 

 elongation of the bones of the face, as shown 

 by the distance of the incisive angle from the 

 central prominence the great depth of the 

 orbits the narrow space between the bases 

 of the horns the length of the jaw and 

 more particularly the extended vertical dia- 

 meter of the condyloid facets of the occipital 

 bone. The elongation of these articular sur- 

 faces in the direction indicated, permits of the 

 head being drawn into a line with the neck, 

 and Prof. Owen states, from observing this 

 action in the living animal, that he has seen 

 it stretched backward beyond this line. 



Horns. In the Giraffe we have a unique 

 example of solid persistent horns, completely 

 invested with a hairy integument. They are 

 placed on two bony elevations, having a 

 position analogous, in some respects, to that 

 of the osseous cores of the Stags ; but, being 

 separated from them b}" a synchondrosis, they 

 are to be regarded as independent develop- 

 ments or " epiphyses " and not " apophy- 

 sial " outgrowths (fig. 328.). As has been al- 

 ready observed, the protuberances are formed 

 in part by the parietal and frontal bones, the 



