THE SURVIVAL OF THE FITTEST 389 



running from near the top of the upper wings to 

 the base of the lower ones. * At the extreme lower 

 point of the latter there is a curved, projecting 

 tail and another much longer one above it. Al- 

 though I often watched closely I could never find 

 it after it alighted in the dense forest. I could see 

 its gorgeous wings as it flew with great rapidity 

 through the hammock; then, as suddenly as the 

 turning out of an electric light, it was gone. One 

 day when I was in the hammock a Timetes flew 

 close by me and vanished within a yard of my face. 

 It seemed to disappear among some dead leaves 

 on a shrub before me and as I peered very closely 

 among them I discovered it, apparently as perfect 

 a dead leaf as any on the bush. The wings were 

 closed and much of the red color had faded, their 

 under surfaces had grown darker and were slightly 

 variegated with a smoky brown exactly the color 

 of the dead leaves. The lower tail was pressed 

 closely against the twig on which it had alighted 

 and formed a perfect petiole. This appeared to be 

 continued up two thirds of the length of the sup- 

 posed leaf as a midrib. This midrib seemed to be 

 actually raised but I afterwards discovered that it 

 is cleverly composed of color markings, so arranged 



