_Illustrations._ 1st. The cloth-dresser, by the aid of this sense, distinguishes the quality, as well as the slightest difference of texture, in the different pieces of cloth. 2d. The miller, from a similar education, quickly detects the quality of flour or meal, by permitting it to pass between his fingers. The difference in the texture of cloths, or the quality of the flour, would not be distinguished by an individual whose tactile sense had not been trained to make nice comparisons. -=-=-=-=-=-=-=-=-=-=-=-= 864. Is this sense susceptible of improvement? What persons cultivate it to a high degree? Give illustration 1st. Illustration 2d. -=-=-=-=-=-=-=-=-=-=-=-= CHAPTER XLII. SENSE OF TASTE. 865. The chief organ of TASTE is the upper surface of the tongue; though the lips, the palate, the internal surface of the cheeks, and the upper part of the oesophagus, participate in this function. ANATOMY OF THE ORGANS OF TASTE. 866. The tongue is a double organ, composed chiefly of muscular fibres, which run in almost every direction. The two sides are so perfectly distinct, that sometimes, in paralysis, one side is affected, while the function of the other remains perfect. It possesses great versatility of motion, and can be moulded into a great variety of shapes. In articulation, mastication, and deglutition, the tongue is an auxiliary to other organs. 867. This organ is abundantly supplied with blood-vessels, having a large artery sent to each side of it. It is also very largely furnished with nerves; it receives nervous filaments from the fifth, ninth, and twelfth pairs of nerves. The branch of the fifth, called the gustatory, is the nerve of taste and sensibility;[21] the twelfth, called the hypo-glossal, of voluntary motion. By means of the ninth, called the glosso-pharyngeal the tongue is brought into association with the fauces, oesophagus, and larynx. It is of obvious importance that these parts should act in concert; and this is effected by the distribution of this nerve. [21] Some physiologists impute the sense of taste to the ninth pair of nerves; others, to the twelfth pair; while others, again, contend that taste is the result of a concurrent action of the fifth, ninth, and twelfth pairs of nerves. -=-=-=-=-=-=-=-=-=-=-=-= 865. What is the chief organ of taste? What other parts participate in the function? 866-870. _Give the anatomy of the organs of taste._ 866. Give the structure of the tongue. 867. Is this organ abundantly supplied with blood? From what source does the tongue derive its nerves? -=-=-=-=-=-=-=-=-=-=-=-=