STUDIES IN NATURE 



they die away. Our ears are arranged to take 

 in these vibrations and send news of them to the 

 brain, by means of which we understand them. 

 Animals, as we know, also have ears and listen 

 attentively ; a dog will sometimes seem to hear 

 a noise before the cause has come near enough 

 for it to be sufficiently loud for us to hear. In 

 the same way, dogs and other animals can dis- 

 tinguish smells which we cannot notice at all. 

 Men who spend their lives out of doors in the 

 country, and especially those races of men who 

 are out of reach of our civilisation, are often 

 found to have powers of hearing, smelling, and 

 even seeing which are greater than those of 

 town-bred people. This is probably because 

 they depend more on these senses for knowledge 

 about the movements of other men, whether 

 friend or enemy, and of animals, whether 

 dangerous or useful as food. It seems likely 

 that if we do not use our senses, we gradually 

 lose the power to do so, and this is a very good 

 reason for trying to increase our field of obser- 

 vation in every way we can. 



Sound, as we should naturally suppose, 

 travels far more easily when there are not many 

 obstacles in its way to turn it aside and other- 

 wise disturb its course. Trees, walls, and hills 

 all prevent its free passage. If we listen to a 

 cart which is being driven down a road, we can 

 often tell when it is going between high banks, 

 through a wood, across an open space, or past 



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