166 THE INSECT WOELD. 



consistency. The result is that the parts which did not cohere 

 in the least when the chrysalis made its first appearance, are 

 fastened together, so that though one could at first observe them, 

 through a layer of transparent fluid, they are hidden now under 

 a sort of veil or cloak. It is necessary to seize then the moment 

 of the birth of the chrysalis, to observe it accurately. 



On examining the pupa before the liquid which pervades these 

 parts has had time to dry, one finds that it resembles the perfect 



Fig. 128. Chrysalis of the Large Tortoise-shell Butterfly (Vanessa polychloros} whose different 



parts have been opened before they were fastened down. 



(a, wings, b b, antennas, f, trunk or proboscis. ) 



insect. One can indeed then separate from each other all the ex- 

 terior parts which belong to the imago. One recognises the head, 

 which is then resting on the thorax ; the two eyes and the antenna) 

 (Fig. 128), which are brought forward like two ribbons ; the 

 wings also brought over the thorax, but these are separated arti- 

 ficially in the drawing we have given after Reaumur ; * and lastly 

 in the space left between the wings, the six legs, and the body of 

 the insect. 



To sum up : the pupa, when it approaches the period for being 

 hatched, is only wrapped in the pupal envelope. Directly it has 

 strength enough to rid itself of its wrapping, the insect frees itself 



* Tome i. p. 382, planche 26, Fig. 7. 



