IX 



TOUCH— GENERAL 



There is a jocular saying that no beer is bad, but some is 

 better than others ! Similarly, it might be said that all senses 

 are complex but some are more complex than others. Each 

 sense has its own kind of complications and that of touch is 

 no exception. 



We are apt to think of touch solely in connection with 

 our fingers, hands, toes and feet, but of course it goes much 

 further than that. Touch and feeling go hand in hand ; and 

 certain sensations which we and other animals have in 

 common are related to the tactile part of our nervous system. 

 Animals can "feel" pain according to their degree of develop- 

 ment ; they are responsive to heat and cold ; and these sensa- 

 tions are in addition to the sense of touch as usually under- 

 stood. 



Humans can feel the shape of things with their fingers 

 and can manipulate machines and tools very largely by 

 means of the tactile sense. Other widely diverse animals can 

 also use a direct sense of touch, and the apes and monkeys 

 probably use this sense in a similar way to ourselves. An 

 elephant's trunk, in addition to being a very enlarged nasal 

 organ, is extremely sensitive at the tip, and the "lips" at 

 the trunk's extremity are capable of great delicacy of 

 touch. (See Plate 9.) 



The tips of the bills of certain birds — snipe, woodcock, 

 curlew, ducks and so on, have an area which is covered with 

 what look, when magnified, like tiny pits, and this area is 

 served by nerves which give the birds in question a sense of 

 touch. This is so fine that the birds can locate and pick up 

 small invertebrates which live below the surface of marshy 

 ground and which are, of course, out of sight. 



The tongues of the parrot family are thick and fleshy, and 

 are sufficiently tactile for the bird to shell a nut or seed held 



