46 THE WONDERS OF INSTINCT 



possess a solid support and a powerful motor. The 

 Cerambyx-larva strengthens its chisels with a stout, black, 

 horny armor that surrounds the mouth ; yet, apart from 

 its skull and its equipment of tools, the grub has a skin 

 as fine as satin and white as ivory. This dead white 

 comes from a copious layer of grease which the animal's 

 spare diet would not lead us to suspect. True, it has 

 nothing to do, at every hour of the day and night, but 

 gnaw. The quantity of wood that passes into its stomach 

 makes up for the dearth of nourishing elements. 



The legs, consisting of three pieces, the first globular, 

 the last sharp-pointed, are mere rudiments, vestiges. 

 They are hardly a millimeter 1 long. For this reason 

 they are of no use whatever for walking; they do not even 

 bear upon the supporting surface, being kept off it by the 

 obesity of the chest. The organs of locomotion are some- 

 thing altogether different. The grub of the Capricorn 

 moves at the same time on its back and belly ; instead of 

 the useless legs of the thorax, it has a walking-apparatus 

 almost resembling feet, which appear, contrary to every 

 rule, on the dorsal surface. 



The first seven segments of the abdomen have, both 

 above and below, a four-sided facet, bristling with rough 

 protuberances. This the grub can either expand or con- 

 tract, making it stick out or lie flat at will. The upper 

 facets consist of two excrescences separated by the mid- 

 dorsal line ; the lower ones have not this divided appear- 

 ance. These are the organs of locomotion, the am- 

 bulacra. When the larva wishes to move forwards, it 



1 .039 inch.— Translator's Note. 



