58 THE BUTTERFLY. 



to the head and remain as relics of a former stage. 

 Rudimentary organs are by no means uncom- 

 mon among animals, even where they never are 

 of the slightest use to the creature during any 

 portion of "its present life. Viewed in the light 

 of modern scientific investigation into the history 

 and relationship of animals, we are quite justified 

 in concluding that organs, having no full devel- 

 opment and no present use, must in some past 

 period have had their full part to play in the 

 economy of the animal in which they are found. 

 " Rudimentary organs," says Darwin,* " may be 

 compared with the letters in a word, still retained 

 in the spelling, but become useless in the pronun- 

 ciation, but which serve as a clue in seeking for 

 its derivation." Such organs, therefore, possess 

 the highest interest, and it was on this account 

 that I felt justified on a preceding page in specu- 

 lating on the possible meaning of the ocellar belt 

 of the chrysalis. 



From the mandibles we pass to the neighboring 

 organs, the maxillae. In the larva, these parts 

 consist, on either side, of a pair of appendages of 

 simple structure, seated on a common hemispher- 

 ical prominence and possessing only the power of 

 withdrawal and protrusion ; the outer and larger 

 consists of several joints ; the inner of only a 



* Origin of Species, sixth ed., p. 402. 



