Sight in Savages. 179 
picture-puzzles, variously labelled “‘ Where’s the 
Cat?” or “Mad Bull,” or“ Burglar,” or “Policeman,” 
or “ Snake in the Grass,” etc., in which the thing 
named and to be discovered is formed by branches 
and foliage, and by running water, and drapery, and 
lights and shadows in the sketch. At first one finds 
it extremely difficult to detect this picture within a 
picture; and at last—with the suddenness with 
which one invariably detects a dull-coloured snake, 
seen previously but not distinguished—the object 
sought for appears, and is thereafter so plain to the 
eye that one cannot look at the sketch, even held 
at a distance, without seeing the cat, or policeman, 
or whatever it happens to be. And after patiently 
studying somescores or hundreds of these puzzles one 
gets to know just how to find the thing concealed, 
and finds it quickly—almost at a glance at last. 
Now the ingenious person that first invented this 
pretty puzzle probably had no thought of Nature, 
with her curious imitative and protective resem- 
blances, in his mind ; yet he might very well have 
taken the hint from Nature, for this is what she 
does. The animal that must be seen to be avoided, 
and the animal that must be seen to be taken, are 
there in her picture, sketched in with such cunning 
art that to the uninstructed eye they form only por- 
tions of branch and foliage and shadow and sunlight 
above, and dull-hued or variegated earth and stones 
and dead and withering herbage underneath. 
It is possible that slight differences may exist in 
the seeing powers of different nations, due to the 
N 2 
