EXPERIMENTS ON PROTECTIVE COLORATION 



481 



the cricket and the grayish-white ashes was greater than that between 

 the former and the dark background. The accompanying sketch 

 (fig. C) shows the arrangement of the backgrounds and the line of the 

 birds' approach (xy) and the point (x) where it stopped to pick up a 

 particle of food. 



Humus Grass 



Grass 



Line of Approach 



Fig. B The figures indicate the positions of the insects on the backgrounds, 

 and the order of their seizure. 



Experiment 14- Figures 4.O and ^3. One Gryllus was placed on 

 scraps of burnt paper and one on ashes. The resemblance between the 

 cricket and the paper was close and the contrast between the former 



Ashes 



Fig. C 



and the ashes was strong. After five minutes the grackle flew to the 

 ground close to the latter background, from which it took the cricket. 

 It then took that on the paper. Although the bird flew directly to the 

 backgrounds in this experiment it apparently did not see the insects 

 until after alighting, for it turned from its first position in order to 

 seize its prey. 



Experiment 15. Figures 2^ and 30. Two Melanoplus were placed 

 on ashes and two on a mixture of dead leaves, straw, and earth, the 



