crtAF. xvm.] OF CELEBES, 281 



Australia. Figure 3 shows the elongated wing of Tachyris 

 zarinda, a native of Celebes, compared with the much 

 shorter wing of Tachyris nero, a very closely allied species 

 found in all the western islands. The difference of form 

 is in each case sufficiently obvious, but when the insects 



themselves are compared it is much more strikmg than 

 in these partial outlines. 



From the analogy of birds, we should suppose that the 

 pointed wing gave increased rapidity of tlight, since it is a 

 character of terns, swallows, falcons, and of the swifts 

 flying pigeous. A short and rounded wing, on the other 

 hand, always accompanies a more feeble or more laborious 



