The Senses. 251 



Such facts have led to the belief that the temperature 

 sense is distinct from that of touch, and has its own nerve 

 fibers and nerve endings. 



Summary. i . The special, senses result from the action of external 

 forces, such as light, heat, etc. 



2. General sensations are referred to our bodies and their condition. 



3. The muscular sense depends on impulses from muscles, tendons, 

 and joints. 



4. The muscular sense and touch aid the sense of sight in giving us 

 correct perceptions of size and form. 



5. Pain is a general sensation. It is a warning the cry of a senti- 

 nel that an enemy has passed the picket line. ^ 



6. Hunger and thirst indicate the need of food and drink. They 

 are local signals of a general want. 



7. The cutaneous sensations are touch, temperature sense, and pain. 



8. There are touch, corpuscles in the papillas of the dermis. 



9. Touch is the most general of the senses. 



10. Touch proper, or pressure sense, is tested by perception of pres^ 

 sure. 



11. Touch localization is tested by discrimination as to the distance 

 of two points of contact. 



12. Temperature is discerned by a special set of nerve fibers. 



13. Sensations are referred to the region of the nerve endings. 



Questions. i . What is the explanation of tickling. 



2. Where does the change occur by which we become more skilled 

 in the sense of touch ? 



3. Why does an emotion, such as shame, make one feel hot ? 



4. If we had no sense of pain, what might result ? 



5. If we pass by a meal time without eating why does the sense of 

 lunger usually disappear ? 



