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I AM I. 



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cells, which lie together somewhat like the leaves in a bud ; 

 hence their name. The innermost cells of each bud differ 

 from the other cells in having a delicate process reaching 

 outwards to the surface, so that there is a small cluster of 

 fine processes coming up to the surface out of each bud. 

 To these innermost cells nerve filaments coming from the 

 glosso-pharyngeal or ninth cranial nerve can be traced. A 

 branch of the fifth cranial nerve is also concerned with taste. 

 If some dissolved quinine is taken into the mouth these 

 delicate processes are influenced by the contact of the 

 quinine solution, and cause the epithelial cells of the bud to 



FIR. 89. Diagram of a circumvallate papilla, and of taste buds. 



A, A circumvallale papilla cut across; <, epidermis; <f, dermis ; /, taste buds; , 

 netve fibres. 



It, Two taste buds ; t, epidermis ; </, dermis ; c, the outer or cover cells shown in tin- 

 lower bud ; M, four inner cells with processes; HI, processes projecting at mouth 

 of buds. 



send impulses along the nerve fibres to the brain, and these 

 impulses make us aware of the bitter taste. The mucous mem- 

 brane of the palate is very similar to that of the tongue, though 

 the papill.i- are not so prominent ; in it too taste buds occur. 



There are four kinds of taste properly so called, namely, the 

 sweet, the bitter, the sour, and the salt. It is with these tastes 

 only that the taste buds just described have to do. But besides 

 tastes proper we have sensations which we call tastes or better 

 " flavours," such as the flavours of meats and drinks, but which 

 are really sensations of smell. The flavour of an onion, for 

 instance, is really the sense of smell excited by odorous particles 



