An Unknown Sense 349 



released them in a room converted into a maze 

 by means of cords stretched in every direction 

 and of heaped-up brambles, how were those 

 animals able to find their way about, to fly 

 quickly, to move to and fro, from end to end 

 of the room, without hitting the interposed 

 articles ? What sense analogous to any of ours 

 guided them ? Would some one tell me and, 

 above all, make me understand ? I should also 

 like to understand how the Ammophila infall- 

 ibly finds her caterpillar's burrow with the aid 

 of her antennae. It is not a case of the sense of 

 smell : we should have to presume it to possess 

 an unparalleled delicacy, while recognizing 

 that it is exercised by an organ in which no 

 provision seems made for the perception of 

 smells. 



What a number of other incomprehensible 

 things do we not ascribe to the insect's sense 

 of smell ! We are satisfied with a word : the 

 explanation is read3^-found, without laborious 

 search. But, if we care to consider the matter 

 thoroughly, if we compare the requisite array 

 of facts, then the chff of the unknown rises 

 abruptly, not to be climbed by the path which 

 we insist on following. Let us then change our 

 path and admit that animals may have other 

 means of information than our own. Our senses 

 do not represent the sum total of the methods 



