no THE SENSES OF ANIMALS 



Earlier on, I made reference to the strong possibility that 

 frogs, toads and newts find their way to breeding ponds by 

 means of smell ; and in water-living animals this naturally 

 brings up the question as to whether such creatures can taste 

 in water. There is evidence that they can do so ; but it must 

 not be forgotten that in fish and terrapins and many other 

 aquatic animals, the sense of smell also plays a strong part 

 in tasting — the water itself may well taste, and this could be 

 one reason why some ponds are well populated with animal 

 life and some are not. 



Scent particles are carried well by water, and substances 

 with a strong taste can, of course, be detected when dissolved 

 in water. However, the difficulties of drawing any clear line 

 between tasting and smelling are great and very hard to put 

 into words. 



The probability that only a few types of birds have a good 

 sense of smell has already been referred to, but it is quite 

 certain that birds can taste and have some powers of dis- 

 crimination in this respect. We can, therefore, say it would 

 seem that at least one group of animals can taste well even 

 though smell is not a sense which is present in all families 

 within that group. Does the converse apply in other groups? 

 Are there any animals among those of high degree that can 

 smell but not taste? It seems unlikely; but much work is 

 being carried out on this subject and, like many other puzzles 

 in the world of living things, the solution to this problem 

 may be fully explained before long. 



Insects discriminate between one kind of taste and another 

 — salt from sweet for instance. Some caterpillars will feed on 

 a number of different food plants, while others will only eat 

 one particular plant. It seems reasonable to assume that 

 taste — in addition to other factors — may play a part in this 

 marked selectivity. (See Plate 8.) 



Fish can taste, and newts can taste ; tortoises and terrapins 

 can taste, though it is worth while noting that these creatures 

 appear to test certain food items before taking them into 

 their mouths ; this testing is carried out by smell, and if the 

 smell of something is repugnant, the substance will not be 

 eaten. 



Crabs and other similar animals which are feeders on 



