240 



Life and Health 



the chief organ of taste ; the nose, of smell ; the eye, of 

 sight ; and the ear, of hearing. 



370. The Organ of Touch. The organ of touch, or tactile 

 sensibility, is the most widely extended of all the special 

 senses, and perhaps the simplest. It is this sense to 

 which we instinctively appeal to escape from the illusions 

 into which the other senses may lead us. It has its seat 

 in the skin all over the body, and in the mucous membrane 

 at the entrance to various passages. All 

 parts of the body, however, have not this 

 sense in an equal degree. 



We learned in Chapter IX that the super- 

 ficial layer of the skin covers and dips in 

 between the papillae, which are richly pro- 

 vided with blood vessels and sensory nerve 

 fibers. Now many of these nerve fibers 

 terminate in oval-shaped bodies about one 

 three-hundredth of an inch long, around 

 fied View of a Pa- which the nerve fibers wind, and which 

 pilia of the Skin, they finally enter. These are called touch 



with a Touch Cor- Qr ^ CQ Uscle and are found in great 



puscle. 



numbers on the fingers and toes, and more 

 scantily in other places, as on the edges of the eyelids 

 (Figs. 104 and 126). 



Again, many of the nerve fibers terminate in corpuscles, 

 the largest about one-twentieth of an inch long, called 

 Pacinian corpuscles. These are most numerous in the palm 

 of the hand and the sole of the* foot. 



^ 371. The Sense of Touch. Touch includes the sense of 

 contact and the sense of pressure. The sense of heat and 

 cold may be regarded as a distinct sense. 



The sense of contact is the most important element in 

 touch. By it we judge of the form, size, and texture of the 



Magni- 



