THK ^r()TI-I. 



35 



pilosis is called a complete metamorphosis, for the 

 stages are very distinct from each otlier. It is also 

 called indirect, because the butterfly or moth reaches 

 its mature form by a roundabout way, through the 

 several stages. 



Mioroscopir Object. 



The color of the wings 

 depends upon the color of 

 the scales. Scales of several 

 different shapes may Ije 

 found upon the Aving of a 

 butterfly. 



ECRi.iPIA MOTH. 



The butterfly has sucking mouth parts. Tlio suck- 

 ing tube is composed of two parts which are homol- 

 ogous to the maxillae of the grasshopper. Two or- 

 gans are said to be homologous wlien they bear the 

 same relation to their respective bodies, no matter how 

 different the organs may l)e in appearance or use. In 

 this case, one pair of organs on the grasshopper has 

 been developed as a pair of jaws, and we call them 

 maxillse. The same organs have been developed on 

 the butterfly as a sucking tube. It is this sameness 

 that constitutes the homology. AVe know that two 

 organs are homologous by their having the same posi- 

 tion or the same structure. 



The labial palpi and the sucking tul)e are the only 

 mouth parts the butterfl}- has. Indications of the 



