454 The Bird 
animals, let us consider some of the more patent cases 
where eggs are coloured for protection— where they 
mimic their surroundings so perfectly that only the most 
careful search reveals their whereabouts. Ostriches and 
Cassowaries are two interesting examples, the former 
bird laying its white eggs upon the white sands of the 
desert; while the cassowary, in the depths of its jungle 
home, incubates a nestful of eggs of the most exquisite 
emerald hue, matching perfectly the green moss upon 
which they rest. I knew of one of these birds confined 
in a small paddock of green grass, whose splendid eggs, 
measuring three by six inches, once remained undiscoy- 
ered for weeks, although laid openly upon the ground. 
Special search was necessary to find even these great eggs. 
If we walk in the woods in June and happen to flush a 
night-hawk from the ground, the most careful scrutiny of 
the place where the bird rose will often fail to reveal to 
our sight what at last our fingers detect—two eggs, their 
shells imbued with the colours of the forest floor. I have 
led persons to a spot on a beach of shells and sand, 
told them that there were twenty-one good-sized eggs 
within a radius of fifteen feet, and seen them utterly baffled. 
The olive-gray, blotched shell of a tern’s egg rests among 
dark pebbles, or more often upon a wisp of seaweed, into 
whose irregularities the hues of the eggs melt and mingle 
perfectly. The Black Skimmer, that most interesting 
bird of our coast, lays its eggs upon the bare sand among, 
or sometimes in, the large clam-shells which the storms throw 
up in windrows. Against man’s systematic search their 
wonderful assimilative colouring is of course often useless, 
