48 THE WONDERS OF INSTINCT 



ture, perchance, be obeying other rules than those of en- 

 vironment? 



Though the useless legs, the germs of the future limbs, 

 persist, there is no sign in the grub of the eyes where- 

 with the Cerambyx will be richly gifted. The larva has 

 not the least trace of organs of vision. What would it 

 do with sight in the murky thickness of a tree-trunk? 

 Hearing is likewise absent. In the never-troubled 

 silence of the oak's inmost heart, the sense of hearing 

 would be a non-sense. Where sounds are lacking, of 

 what use is the faculty of discerning them? Should 

 there be any doubts, I will reply to them with the follow- 

 ing experiment. Split lengthwise, the grub's abode 

 leaves a half -tunnel wherein I can watch the occupant's 

 doings. When left alone, it now gnaws the front of its 

 gallery, now rests, fixed by its ambulacra to the two sides 

 of the channel. I avail myself of these moments of quiet 

 to inquire into its power of perceiving sounds. The 

 banging of hard bodies, the ring of metallic objects, the 

 grating of a file upon a saw are tried in vain. The ani- 

 mal remains impassive. Not a wince, not a movement of 

 the skin ; no sign of awakened attention. I succeed no 

 better when I scratch the wood close by with a hard point, 

 to imitate the sound of some neighboring larva gnawing 

 the intervening thickness. The indifiference to my noisy 

 tricks could be no greater in a lifeless object. The ani- 

 mal is deaf. 



Can it smell? Everything tells us no. Scent is of 

 assistance in the search for food. But the Capricorn grub 

 need not go in quest of eatables: it feeds on its home, 



