OF THE NUBIAN GIRAFFE. 223 
quill (fig.2.k.), occurred immediately anterior to the genio-glossus,and full six inches from 
the apex of the tongue. In the specimen here described there was a marked difference 
in the size of the two lingual arteries: the left was the larger, and, beyond the preceding 
anastomosis, formed the principal channel for the supply of the free prehensile part of 
the tongue with blood, which part thus displays more singleness and unity in its organic 
composition than in man and most other Mammalia, in which the arteries supplying the 
two lateral moieties of the tongue are equal in size, and have only a slight anastomosis near 
its apex. The lingual veins in the Giraffe are of large size and present a slight plexiform 
arrangement beneath the baseof the tongue (fig. 2. h. h.). Thevein, together with the lingual 
artery which it accompanies, along the inner side of the stylo-glossus muscle, is covered by 
a thin stratum of transverse fibres, which pass from the middle line of the under surface 
of the tongue over the stylo-glossi to the upper surface of the tongue, and when in action 
would serve to compress the vessels, and at the same time elongate the relaxed fibres of the 
stylo-glossi ; but the space surrounding these vessels is quite inadequate to allow of their 
distention, so as in any degree to affect the size or motion of the tongue. The whole of 
the movements of the tongue, in fact, are due to muscular action : any physiologist who 
has felt the firm but regulated grasp of the tongue of the Giraffe, when twined round the 
finger, must have been convinced that the action was totally dissimilar to that sudden and 
fitful force arising from vascular or erectile action. The muscular fibres in the free and 
flexible part of the tongue present an arrangement adequate to all its movements. The 
stylo-glossi and inferior linguales expand into a layer of longitudinal fibres, about a line 
in thickness, covering the whole of the inferior surface of the free portion of the tongue, 
and becoming continuous at the sides, with a corresponding but thicker stratum of lon- 
gitudinal fibres on the upper surface of the tongue ; these longitudinal muscles inclose a 
mass of fibres, which run in the transverse direction. The action of these transverse 
fibres, combined with that of several short vertical fibres near the margins, and of 
those forming the thin circular stratum surrounding the stylo-glossi at the middle part 
of the tongue, serves to attenuate or diminish the transverse diameter of the tongue and 
increase its length; while thus rigidly extended, the apew of the tongue can be curved 
upwards or downwards by the superficial longitudinal fibres, which are less intermingled 
with the transverse fibres than in the tongues of most other Mammalia: the contraction 
of the longitudinal fibres taking place with the relaxation of the transverse ones, produces 
the retraction of the whole organ. 'The nerves of the tongue present the same dispo- 
sition as those in ordinary Ruminants, but the ninth pair is relatively larger than the 
branch from the fifth pair: the nerve which runs along the inner or under surface of the 
stylo-glossi towards the free extremity of the tongue is remarkable for its beautifully 
wavy course (fig. 2. g.), by which it is accommodated to the variations which occur in 
the length of the organ in the living animal. 
The epithelium is thickest at the apex of the tongue, on the upper surface of which 
it is developed into numerous minute retroverted spines, which occasion the rasp-like 
262 
