304 SOCIAL LIFE IN THE INSECT WORLD 



A profound transformation is necessary to bring the 

 wings to their final perfection. The inner changes are 

 already at work ; liquids are solidifying ; albuminous 

 secretions are bringing order out of chaos ; but so far 

 no outward sign betrays what is happening in the mys- 

 terious laboratory of the organism. All seems inert and 

 lifeless. 



In the meantime the posterior limbs disengage them- 

 selves. The great haunches become visible, streaked on 

 the inner faces with a pale rose, which rapidly turns to a 

 vivid crimson. Emergence is easy, the thick and muscu- 

 lar upper portion of the haunch preparing the way for 

 the narrower part of the limb. 



It is otherwise with the shank. This, in the adult 

 insect, is armed along its whole length by a double 

 series of stiff, steely spines. Moreover, the lower ex- 

 tremity is terminated by four strong spurs. The shank 

 forms a veritable saw, but with two parallel sets of teeth ; 

 and it is so strongly made that it may well be compared, 

 the question of size apart, to the great saw of a quarry- 

 man. 



The shank of the larva has the same structure, so that 

 the object to be extracted is enclosed in a scabbard as 

 awkwardly shaped as itself. Each spur is enclosed in a 

 similar spur ; each tooth engages in the hollow of a 

 similar tooth, and the sheath is so closely moulded upon 

 the shank that a no more intimate contact could be 

 obtained by replacing the envelope by a layer of varnish 

 applied with a brush. 



Nevertheless the tibia, long and narrow as it is, issues 

 from its sheath without catching or sticking anywhere. 

 If I had not repeatedly seen the operation I could not 



