492 



THE DESCENT OF MAN. 



would manifestly leave a much deeper indentation at the 

 divergent than at the convergent end. It is also manifest 

 that if the convergence were strongly pronounced and the 

 confluence complete, the indentation at the convergent end 

 would tend to disappear. 



The tail-feathers in both species of the peacock are en- 

 tirely destitute of ocelli, and this apparently is related to 

 their being covered up and concealed by the long tail- 

 coverts. In this respect they differ remarkably from the 



Figr. 55. Part of a tail-covert of Poly- 

 plectron chinquis, with the two 

 ocelli of natural size. 



Fig. 56. Part of a tale-covert of Poly- 

 plectron malaccense, with the two 

 ocelli, partially confluent, of nat- 

 ural size. 



tail-feathers of Polyplectron, which in most of the species 

 are ornamented with larger ocelli than those on the tail- 

 coverts. Hence I was led carefully to examine the tail- 

 feathers of the several species, in order to discover whether 

 their ocelli showed any tendency to disappear; and to my 

 great satisfaction this appeared to be so. The central tail- 

 feathers of P. napoleonis have the two ocelli on each side 

 of the shaft perfectly developed; but the inner ocellus be- 

 comes less and less conspicuous on the more exterior tail- 

 feathers, until a mere shadow or rudiment is left on the 

 inner side of the outermost feather. Again, in P. malac* 



