THE ORGANS OF THE SENSES AND 

 THE COMMON INTEGUMENT. 



THE organs of the senses may be divided into (a) those of the special senses of 

 taste, smell, sight, and hearing, and (6) those associated with the general sensa- 

 tions of heat, cold, pain, pressure, etc. 



THE PERIPHERAL ORGANS OF THE SPECIAL SENSES. 



THE ORGAN OF TASTE (ORGANON GUSTUS). 



The peripheral gustatory or taste organs consist of certain modified epithelial 

 cells arranged in flask-shaped groups termed gustatory calyculi (taste-buds), which 

 are found on the tongue and adjacent parts. They occupy nests in the stratified 

 epithelium, and are present in large numbers on the sides of the papillae vallatae 

 (Fig. 850), and to a less extent on their opposed walls. They are also found on the 



Central lamina of 

 corium 



Lateral lamina 

 Gustatory calyculusj. 



Section across a sinus- fflH 

 like vein, traversing 

 whole length offoliw 



Serous gland 



Nerve bundles ." /< "" <Sr 



FIG. 850. Vertical section of papilla foliata of the rabbit, crossing the folia. (Ranvier.) 



fungiform papillae over the back part and sides of the tongue, and in the general 

 epithelial covering of the same areas. They are very plentiful over the fimbriae 

 linguae, and are also present on the under surface of the soft palate, and on the 

 posterior surface of the epiglottis. 



Structure. Each taste bud is flask-like in shape (Fig. 851), its broad base resting on the corium, 

 and its neck opening by an orifice, the gustatory pore, between the cells of the epithelium. The 

 bud is formed by two kinds of cells: supporting cells and gustatory cells. The supporting cells 

 are mostly arranged like the staves of a cask, and form an outer envelope for the bud. Some, 

 however, are found in the interior of the bud between the gustatory cells. The gustatory cells 

 occupy the central portion of the bud ; they are spindle-shaped, and each possesses a large spherical 



(991) 



