440 NATURAL HISTORY [chap, xviii. 



other part of the world. It is most strongly manifested in 

 the Papilios and the Pieridse, and consists in the fore- 

 wings being either strongly curved or abruptly bent near 

 the base, or in the extremity being elongated and often 

 somewhat hooked. Out of the 14 species of Papilio in 

 Celebes, 13 exhibit this peculiarity in a greater or less 

 degree, when compared with the most nearly allied species 

 of the surrounding islands. Ten species of Pieridae have 

 the same character, and in four or five of the Nymphalidse 

 it is also very distinctly marked. In almost every case 

 the species found in Celebes are much larger than those of 

 the islands westward, and at least equal to those of the 

 Moluccas, or even larger. The difference of form is how- 

 ever the most remarkable feature, as it is altogether a new 

 thing for a whole set of species in one country, to differ in 

 exactly the same way from the corresponding sets in all 

 the surrounding countries ; and it is so well marked, that 

 without looking at the details of colouring, most Celebes 

 Papilios and many Pieridse, can be at once distinguished 

 from those of other islands by their form alone. 



The outside figure of each pair here given, shows the 

 exact size and form of the fore-wing in a butterfly of 

 Celebes, while the inner one represents the most closely 

 allied species from one of the adjacent islands. Figure 1 

 shows the strongly curved margin of the Celebes species, 

 Papilio gigon, compared with the much straighter margin 



