LIFE-HISTORY OF BUTTERFLIES 245 



Within all is stir and change. The larval body is 

 being dissolved and remoulded to fit the new existence. 

 The creeping muscles of the caterpillar are broken 

 down and rebuilt to form the flight muscles of the 

 butterfly. The jaws are abandoned, and the lips 

 transformed into an elaborate sucking-tube. The 

 digestive tube is altered to assimilate fluid instead of 

 solid food. The compound eyes undergo their intricate 

 development, and the nervous system which is to 

 control the new and complex organisation is itself 

 undergoing rapid concentration. In dimness and 

 stillness, without any perceptible controlling mecha- 

 nism, the tissues of the caterpillar are reformed and 

 the basis of the future responses is laid down. The 

 specific characters of structure and of colouring are 

 being added. When these changes are in process 

 the use of certain ridges and spines becomes clearer. 

 The delicacy of the internal organs is extreme, and 

 any pressure would deform them ; hence one reason for 

 the presence of projecting spines upon which the stress 

 may fall, and so be diverted from the inner yielding 

 skin. 



When the metamorphosis is complete the pupal 

 skin cracks, and the butterfly, still with intricately 

 convolved appendages, steps out. Its surface is wet, 

 but as the air fills its breathing tubes, the limbs 

 and wings dry and strengthen. It clings tenaciously 

 to its surrounding holdfasts, whilst its muscles gain 

 tone, and the nervous system begins to control the 

 new mechanism. Finally the response to the new order, 



