278 



KATUiiJi lusrour 



[CHAP, XVI It 



Mimy gi'oups of insects appear to be. especially subject 

 to local influeuces. their forms and colonrs changing witli 

 each change of conditions, or even with a cliange of luc^ility 

 where the conditions seem almost identitial. We shouUi 

 IheR'fore aiiticiiiate that tlio individuality manifested in 

 tlie higher animals ■would be still more prominent in these 

 creatm-es with less staltle organisms. On the other hand, 

 however, we have to consider that the dispersion and 

 migi'atioTi of insects is much more easily eflected than 

 that of mammals or even of birds. They are much more 

 likoly to be carried away by violent winds; their eggs 

 may "be caiTied on leaves either by storms of wind or by 

 floating trees, and their lar\-;e mid pupre, often bnried in 

 trunks of tree« or enclosed in waterproof cocoons, may be 

 floated for days or weeks im injured over the ocean. These 

 facilities of dListribution tend to assimilate the productions 

 of adjacent lands in two ways : first, by direct mutual 

 interchange of species; and secondly by repeated immi- 

 grations of fresh individuals of a species common to other 

 islands, which by intercrossing, tend to obliterate the 

 changes of form and colour, which difference of condi- 

 tions might otherwise produce. Bearing these facts in 

 mind, we sluiU find that the individuality of the insects of 

 Celebes is even greater than we have any reason to expect. 



Yov the purpose of insuring accuracy in comparisons 

 with other islands, 1 shall confine myself to those groups 

 -.viiiuh are best known, or which 1 have myself carefully 

 studied. Beginning with the Pa[»ilionidfe or Swallow- 

 tailed buttcrllies, Celebes possesses 24 species, of wliich the 

 large number of 18 are not found in any other island. If 

 we compare this with Borneo, wliicb out of 29 sjKJcies b:is 

 only tvvtt not found elsewhei-e, the dillerence is as striking 

 a.^ anything can be. In the family of the Pierid<e, or white 

 Ijuttcrtlies, the diflPerence is not quite so great, owing 

 perhaps to the more wandering habits of the group ; but 

 it is still veiy remarkable. Out of 30 species inhabiting 

 Celebes, 19 are peculiar, while Java (from which more 

 species are known than fmm Sumatra or Borneo), out of 

 37 species has only 13 peculiar. The Danaida^. are large, 

 but weak-tlying buttertlies, which frequent forests ajid 

 gardens, and are plainly but oiten very richly coloured. 



