SUPPORT, MOTION, AND SENSATION 363 



lateral line. The entire surface of the body of \ertehrates in general 

 is practically covered with receptors capable of iiitcrpretinp; touch or 

 pressure, temperature, and pain. 



These integumentary receptors, of which there are many modifica- 

 tions, are not located with imiform density over the body surface. 

 It has been estimated that there are between 3,000,000 and 4,000,000 

 pain, 500,000 pressure, 150,000 cold, and 16,000 warm receptors 

 located in the human skin. 



An understanding of the sensations and impulses which are received 

 from the organs of special sense is the primary means of keeping our- 

 selves informed about changes taking place in our immediate sur- 

 roundings. From these sensations and impulses are built up definite 

 reactions as well as certain convictions or attitudes which enable us to 

 secure the maximum (^r minimvmi out of life. 



SUGGESTED READINGS 



Clendenning, L., The Human Body, Alfred A. Knopf, Inc., 1930. Pp. 53-70, 



223-250. 



More popular reading. 

 Howell, W. H., A Textbook of Physiology, 12th ed., W. B. Saunders Co. 



1933. Chs. I-V. 



A thorough technical account of the j)hysiolog3' of muscle and nerve. 

 Rogers, C. G., Textbook of Com-parative Physiology, McGraw-Hill Book Co., 



1927. Chs. XXVI and XXVIII. 



Advanced account from the comparative viewpoint. 

 Wells, H. G., Huxley, J. S., Wells, C. P., Science of Life, Doubleday, Doran 



& Co., 1931. Pp. 32-38, 523-524, 697-698, 1200-1226. 



Popular account with emphasis on man. 



