Protective Coloration in its relation to Mimiery, etc. 569 
Any one who has tried to catch a snake in the grass will 
see at a glance why Nature tries to direct an enemy’s 
attention behind the animal he is hunting. The snake 
for ever proves to be further on. It is hard to set one’s 
foot far enough ahead as he moves, just as a wing-shot 
tends to shoot behind. Now Nature, realizing this, offers 
the enemy the utmost inducement to strike too far back. 
The strong cross-bars of the Reeves or the Copper Pheasant, 
while visually they cut the tail to pieces when it is still, 
are, as with the Peacock, by far the most visible part of the 
bird as soon as he moves. The reason of this is that in 
forward motion the longitudinal markings scarcely show, 
while the transverse ones become conspicuous. To prove 
this, any reader has only to blacken a few points an inch 
or so apart on a white cord, and then move the cord longi- 
tudinally, drawn tight across some aperture a few yards 
away, the cord being only visible where it crosses the 
aperture. He will see that its motion is distinguishable 
much farther off when the spots are in sight than when 
the wamarked cord is passing. The spots correspond to 
the tail-marks of the Pheasant, and the cord where it is 
not spotted represents the bird’s longitudinal markings, 7. e. 
his body-markings. 
Before closing I beg to say that I do not mean that I 
am convinced that Mimicry and Common Warning Colours 
have no hand in these resemblances. I merely point out 
that the coloration of every individual of the “ mimicking 
groups” of butterflies seems to be the best conceivable for 
effacing the aspect of its wearer, and also that it is per- 
fectly conceivable that an external influence, like super- 
abundance of certain very sweet flowers, could do the 
whole thing. 
