894 



PHYSIOLOGY OF THE DOMESTIC ANIMALS. 



(Pig. 410). They are also found to a less extent on the fungiform papillae, 

 the papillae of the soft palate and uvula, and even on the posterior surface 

 of the epiglottis and on the inner side of the arytenoid cartilages, and on 

 the vocal coi'ds. These latter localities would seem to throw doubt upon 

 the connection between these structures and their connection with the 

 sense of taste, but the fact that after section of the glosso-pharyngeal 

 nerve these taste bulbs degenerate, and that direct communication can 

 be traced between this nerve and these cells, would seem to place their 

 position as the terminal organs of the special nerve of taste beyond doubt. 

 These taste bulbs are barrel-shaped and consist of series of nucleated 

 external, almost cylindrical protecting cells, arranged so as to leave an 

 opening, — the so-called gustatory pore. Lying in the axis of such a 

 structure are found from one to ten gustatory cells, some provided with 



Fig. 410.— Structure of the Gustatory Organs. (Landois.) 

 I. Transverse section of a circumvallate papilla: W, the papilla; y. v, the wall in section- R R the 

 circular slit of fossa ; K. K, the taste bulbs in position ; N, N, the nerves. II. Isolated taste buibs : D 

 supporting or protective co Is; K, under end; E, free end, open, with the projecting apices of the taste 

 cells. III. Isolated protective cell, d, with a taste cell,- e. 



delicate processes at their free extremities, while their lower, fixed ends 

 become continuous with the non-meclullated terminations of the nerve of 

 taste (Figs. 411, 412, and 413). 



The tongue of mammals in its general characteristics resembles that 

 of man, and similar papillae are found on it. In the different domestic 

 animals, especially in the herbivora, the sense of taste must differ from 

 that in the carnivora, although we have every day evidences of its exist- 

 ence, and we know that in the herbivora likewise decided preference for 

 different substances are manifest, which evidently must be dependent upon 

 differing degrees of excitation of the sense of taste, although the expla- 

 nation of that fact is yet entirely beyond us. Thus, as to why a horse 

 should prefer oats to hay, or the latter to straw, must evidently be ex- 

 plained by some difference in impression of the substances on the nerve 

 of taste and not a mere matter of instinct. 



