128 THE UNIVERSE. 



metamorphoses. We must come to the period of the Re- 

 naissance, and see Redi begin to trace their history with a 

 steady hand. To the illustrious physician of Florence suc- 

 ceeded Malpighi, the great anatomist, and Goedart, a sim- 

 ple and excellent observer, who, in a book as rare as it is 

 curious, brought under notice each caterpillar and its but- 

 terfly. 



At birth the insect is always wingless. The apparatus 

 for flying is only developed at the last stage of its existence, 



that which is consecrated solely to reproduction. The 

 young creature generally presents itself under the form of a 

 worm, to which Linnaeus gave the name of larva, or mask, 



an ingenious reminder that this worm is only a kind of 

 preliminary disguise, beneath which is hidden the brilliant 

 livery of the perfect insect. 



The first period of life is given up entirely to develop- 

 ment ; the larva does nothing but eat and grow. But at 

 a given time its activity ceases ; it shrivels up, casts off its 

 skin, takes on a new form, and becomes motionless. It is 

 then that the name of nymph is given to it. This is a mere 

 transitory state, and in this kind of temporary sepulchre 

 the unfinished existence of the caterpillar is annihilated, and 

 that of the perfect insect begins. 



The transfiguration is as complete in the interior as at 

 the surface. At a certain time the whole organism seems 

 resolved into a homogeneous paste, from which springs the 

 new living being. Generally the nymph is only covered 

 with a brown winding-sheet of the most modest kind ; it 

 looks like an immovable mummy enveloped in bandages, 

 but sometimes, in imitation of monarchs, it carves out for 



