igS THE SENSES OF ANIMALS 



to mark out territories, and in receiving warning of the 

 approach of enemies. It is obvious, as Maxwell Knight has 

 pointed out in Part I, from the behaviour of the other 

 mammals that their sense of smell is very much more delicate 

 and has immensely greater powers of discrimination than 

 has ours. In man the sense of smell has, in a large measure, 

 fallen into disuse and lost its accuracy ; in our civilization it 

 has even become a somewhat disreputable sense. It is per- 

 fectly acceptable to smell a flower or fruit in order to enjoy 

 a delicious scent, or to appreciate the bouquet of wine, but 

 it is not generally regarded as well-mannered to sniff at an 

 egg or slice of meat to test its freshness — such actions are 

 regarded as animal-like and almost indecent. Having lost 

 our sense of smell we affect to despise what we lack. 



Aquatic mammals, too, can have little use for a sense of 

 smell for, being air-breathers, they must all shut their noses 

 when their heads are beneath the surface of the water. 

 Whales, dolphins and porpoises use their noses, which have 

 moved to the top of the head and become blow-holes, only 

 when they come up to breathe, and although they may have 

 some sense of smell they can have few opportunities for using 

 it. As we have seen, they have developed other senses, par- 

 ticularly that of hearing, to an extraordinary degree of per- 

 fection, no doubt at least in part as a compensation for being 

 denied the use of their noses. Little is known of the lives of 

 the sea-cows, the manatee and dugong of tropical coasts and 

 rivers, but as they too spend most of their time under water, 

 and open their noses only when they come to the surface to 

 breathe, it is probable that they do not possess an acute sense 

 of smell. 



The seals, on the other hand, certainly preserve a good 

 sense of smell. Although they cannot use their noses when 

 hunting their prey under water, they do use them when they 

 come out on to the land. Seals generally congregate in large 

 numbers on their breeding grounds, and when a seal mother 

 looks for her pup in a crowded "rookery", she identifies it 

 by smell, and can pick it out from hundreds of other pups 

 against the overpowering background aroma. (See Plate 

 i6.) 



Birds are generally held to have little or no sense of smell 



