6o Elementary Zoology. 



they may be recognized as rudiments, as in the caterpillar of 

 the moth. Coincidently with this histolysis, or breaking down 

 of tissues, occurs an histogenesis, or building up of tissue. 

 This largely takes place from the so-called "imaginal discs," 

 which are buds of the outer layer ; but other of the internal 

 organs are reproduced by reformation of the disrupted tissues 

 of the corresponding larval organs. It seems to be mainly the 

 external parts that are formed from the imaginal discs. 



