130 



IV. 



THE MALAYAN PAPILIONID^ OR SWAL- 

 LOW-TAILED BUTTERFLIES, AS ILLUS- 

 TRATIVE OF THE THEORY OF NATURAL 

 SELECTION. 



Special Value of the Diurnal Lepidoptera for enquiries 

 of this nature. 



WHEN the naturalist studies the habits, the structure, 

 or the affinities of animals, it matters little to which 

 group he especially devotes himself; all alike offer him 

 endless materials for observation and research. But, 

 for the purpose of investigating the phenomena of geo- 

 graphical distribution and of local, sexual, or general 

 variation, the several groups differ greatly in their 

 value and importance. Some have too limited a range, 

 others are not sufficiently varied in specific forms, 

 while, what is of most importance, many groups 

 have not received that amount of attention over the 

 whole region they inhabit, which could furnish mate- 

 rials sufficiently approaching to completeness to enable 

 us to arrive at any accurate conclusions as to the 

 phenomena they present as a whole. It is in those 

 groups which are, and have long been, favourites with 

 collectors, that the student of distribution and varia- 

 tion will find his materials the most satisfactory, from 

 their comparative completeness. 



