Page:The Zoologist, 4th series, vol 3 (1899).djvu/583

Rh it disappeared, then, rising cautiously, it exposes the tip of its nose above the surface, at the same time giving it a rotary motion like that of a water-bug at play. The unwary bird on the wing, seeing the object near by, alights to catch it, while the Sea-lion at the same moment settles beneath the waves, and at one bound, with extended jaws, seizes its screaming prey, and instantly devours it. Waterton has given a very similar suggestion. Beneath some agitated birds, and in the long grass, he saw what was apparently "a pale green Grasshopper," fluttering as though entangled in it. "Nothing more remained to be done but to wait in patience till it had settled, in order that you might run no risk of breaking its legs in attempting to lay hold of it while it was fluttering—it still kept fluttering, and, having quietly approached it, intending to make sure of it—behold, the head of a large Rattlesnake appeared in the grass close by.... What had been taken for a Grasshopper was, in fact, the elevated rattle of the snake." Aflalo has remarked:—"The snake's power of fascinating birds is another moot point, on which Dr. Stradling has offered about the best suggestion, fully endorsed in Miss Hopley's charming book. His opinion is that the birds mistake the quivering tongue for a worm or insect, and that organ, considered by the ignorant to be endowed with 'stinging powers,' may consequently act as a bait to lure the incautious food within reach of the fatal jaws." The Tree-Frog (Hyla) is of a light green colour when seated upon a light green leaf, but becomes dark brown when transferred to dark surroundings. "Hence this animal adapts itself to the colour of its environment, and thus gains protection from its enemies."