The Senses of Animals. 253 



to admit of no alternative explanation. Moisten, for 

 example, the antennae of a cockroach with a solution of 

 Epsom salts or quinine, and watch him suck it off; or 

 repeat F. Will's experiments on bees, tempting them with 

 sugar, and then perfidiously substituting pounded alum. 

 The way in which these little insects splutter and spit 

 suggests that, whatever may be the psychological effect, 

 the physiological effect is analogous to that produced in 

 us by an exceedingly nasty taste. Here smell would seem 

 to be excluded. Forel, moreover, mixed strychnine with 

 honey, and offered it to his ants. The smell of the honey 

 attracted them, but when they began to feed, the effect of 

 the taste was at once evident. 



The organs of taste in insects are probably certain 

 minute pits, in each of which is a delicate taste-hair, 

 which, in some cases, is perforated at the free end. They 

 occur in the maxillae and tongue in ants and bees, and on 

 the proboscis of the fly. 



In many of the invertebrates, the crayfish and the earth- 

 worm, for example to take two instances from very different 

 groups observation seems to show that a sense of taste is 

 developed, for they have marked and decided food-pre- 

 ferences. Nevertheless, the existence of special organs for 

 this purpose has not been definitely proved. 



The sense of taste no doubt ministers to the enjoyment 

 of life. But, presumably, it has been developed in sub- 

 servience to the process of nutrition. Primarily, taste was 

 not an end in itself, but was to guide the organism in its 

 selection of food that could be assimilated. Nice and nasty 

 were at first, and still are to a large extent, synonymous 

 with good-for-eating and not-good-for-eating. With un- 

 wonted substances, however, its testimony may be false. 

 Sugar of lead is sweet, but fatal. Brought to a new 

 country, cattle often eat, apparently with relish, poisonous 

 plants. Still, under normal circumstances, the testimony 

 of taste is reliable. 



The sense of smell is, to a large extent, telaesthetic. It 



