86 THE BUTTERFLY VIVARICM. 



and have yet produced Moths, or Butterflies, as 

 different as possible from those produced by the 

 English species which they so- closely resembled. 

 There are, however, instances of an opposite kind, 

 which make the whole arrangement appear still 

 more capricious. The Caterpillar of the Currant- 

 moth, for instance, is white, spotted with black and 

 orange, like the perfect insect ; and several other 

 instances might be cited, but they form a very 

 small minority. 



The Growth of Caterpillars is sometimes very 

 rapid — at other tmes quite the reverse. In some 

 cases the increase of size after hatching is enormous; 

 the weight of the Cossus, when full grown, as we 

 are told by Lyonnet, being 72,000 times greater than 

 when first hatched ; but then he is very long lived. 



The growth takes place most rapidly after 

 each moult or change of skin. "The head of the 

 Silk-worm, after casting its skin, becomes almost 

 immediately four times its previous size," says Mal- 

 pighi; but then it is a voracious feeder, and con- 

 sumes in thirty days above an ounce of leaves, thus 

 devouring above 60,000 times its own original 

 weight, which is, when hatched, only about the 

 hundredth part of a grain. I may here suggest that 

 the Vivarium is exceedingly well calculated for the 



