98 TIIK CKNKSIS OF SPKCIES. [Cuai'. 



able varieties from Ihc adjacent islands, of Bonru and New 

 Guinea, it is of a golden yellow, hardly inferior in brilliancy 

 to its color in the male sex. The female of OrnltJioptcra 

 I^ianuts (inhabiting Amboyna and Ceram exclusively) is 

 of a pale dusky-brown tint, while in all the allied species 

 the same sex is nearly black, with eonlra(;ted white mark- 

 ings. As a third example, the female of l\q>ilio XJlysses 

 has the blue color obscured by dull and dusky litits, while 

 in the closely-alUed species from the sunounding islands, 

 the faendes are of almost as brilliant an azure blue as the 

 males. A ])arallel case to this is the occurrence, in the 

 small islands of Goram, ]\bitabello, Ke, and Aru, of several 

 distinct species of Eupla'a and Diadema, having broad 

 bands or patches of white, which do not exist in any of 

 the allied species from the larger islands. These facts 

 seem to indicate some local inlluence in modifying ccjlor, 

 us unintelligible and almost as remarkable as that which 

 has resulted in the modifications of form previously de- 

 scribed." 



After endeavoring to explain some of the facts in a way 

 to be noticed directly, Mr. ^yallace adds : ^° " But even the 

 conjectural explanation now given fails us in the other cases 

 of local modilication. ANHiy the species of the Western 

 Islands should be snuiller than those farther east; whv 

 those of Amboyna should exceed in size those of Gilolo 

 and New Guinea ; why the tailed species of India should 

 begin to lose that appendage in the islands, and retain no 

 trace of it on the borders of the Pacific; and why, in three 

 separate cases, the females of Amboyna species should be 

 less gayly attired than the corresponding females of the sur- 

 rounding islands, are questions which we cannot at })resent 

 attempt to answer. That they depend, however, on some 

 general principle is certain, because analogous facts have 

 been observed in other parts of the woild. !Mr. Bates in- 



"5 "Natural Selection," p. 177. 



