11 ON ANIMAL LIFE 43 



ments we find the utmost differences of form 

 and size and structure. Even the same in- 

 dividual often goes through great changes. 



GROWTH AND METAMORPHOSES 



The development, indeed, of an animal 

 from birth to maturity is no mere question 

 of growth. The metamoi;phoses of Insects 

 have long excited the wonder and admiration 

 of all lovers of nature. They depend to a 

 great extent on the fact that the little 

 creatures quit the egg at an early stage of 

 development, and lead a different life, so 

 that thie external forces acting on them, 

 are very different from those by which they 

 are affected when they arrive at maturity. A 

 remarkable case is that of certain Beetles 

 which are parasitic on Solitary Bees. The 

 young lava is very active, with six strong 

 legs. It conceals itself in some flower, and 

 when the Bee comes in search of honey, leaps 

 upon her, but is so minute as not to be per- 

 ceived. The Bee constructs her cell, stores it 



