132 THE MALAYAN PAPILIONID1E AS 



members exhibit no appreciable change. The wings 

 of Butterflies, as Mr. Bates has well put it, "serve 

 as a tablet on which Nature writes the story of the 

 modifications of species ; " they enable us to perceive 

 changes that would otherwise be uncertain and diffi- 

 cult of observation, and exhibit to us on an enlarged 

 scale the effects of the climatal and other physical 

 conditions which influence more or less profoundly 

 the organization of every living thing. 



A proof that this greater sensibility to modifying 

 causes is not imaginary may, I think, be drawn from 

 the consideration, that while the Lepidoptera as a 

 whole are of all insects the least essentially varied in 

 form, structure, or habits, yet in the number of their 

 specific forms they are not much inferior to those 

 orders which range over a much wider field of nature, 

 and exhibit more deeply seated structural modifica- 

 tions. The Lepidoptera are all vegetable-feeders in 

 their larva-state, and suckers of juices or other liquids 

 in their perfect form. In their most widely separated 

 groups they differ but little from a common type, 

 and offer comparatively unimportant modifications of 

 structure or of habits. The Coleoptera, the Diptera, 

 or the Hymenoptera, on the other hand, present far 

 greater and more essential variations. In either of 

 these orders we have both vegetable and animal- 

 feeders, aquatic, and terrestrial, and parasitic groups. 

 Whole families are devoted to special departments in 

 the economy of nature. Seeds, fruits, bones, car- 

 cases, excrement, bark, have each their special and 



