SPECIAL SENSES OF INSECTS. 13 



to find their mates when the antennae have been removed 

 or coated. On the wings of the big red-brown monarch 

 butterfly are pockets in which are carried scent scales. 

 Ants are thought to be able to perceive odors in so far 

 as to recognize members of their own colony, the path 

 over which a nest-mate has passed or which they them- 

 selves have recently traversed, and to know an enemy 

 by the fact that the new ant smells different from their 

 nest-mates. 



There are plenty of instances which might be cited 

 to prove that man is really inferior to many of the lower 

 animals in the small range of discrimination possible in 

 his olfactory sense. The elephant, the deer, the fox, 

 the wolf, the dog, all bear evidence to an olfactory sense 

 wonderful in its development. Our impressions of 

 delight, aversion; comfort, danger; friend, foe, are more 

 often the result of mental processes. In most affairs of 

 life we think why we should feel, rather than instinctively 

 feel without thinking. Yet, in cases so new that no 

 previous experience could reason out an explanation, we 

 may act from instinctive feeling we say that we scent 

 danger. There is no question that this sense played an 

 important part in the life of primitive man as it does to- 

 day in the preservation of lower animals. It is certain 

 that some insects, at least, if not the majority of them, 

 find their food by the sense of smell. The food-getting 

 instinct is probably the lowest though the most valuable 

 of the instincts, and the sense of smell is surely one of its 

 valuable servants. 



Touch. 



The sense of touch is, with human beings, entirely a 

 superficial sense, a contact sense, capable of stimulation 



