04 RAMBLES ABOUT HOME. 



and darts down when frightened, I would throw a grass- 

 hopper into the water. In an instant, the nearest roach 

 would dart toward it, and usually seize it ; but at the same 

 time the hindmost roach would rush forward with equal 

 promptness, although, of course, it could not have seen 

 the grasshopper, and knew not why it darted forward, 

 except for the reason that it felt the necessity of doing 

 precisely as its neighbors. Then I would change my tac- 

 tics, and throw a grasshopper into the middle of the school. 

 In such a case, the nearest ahead of the insect would 

 turn about, though they were seldom in time to catch it, 

 and the fishes farthest ahead would likewise all turn 

 about, apparently for no other reason than because those 

 behind them did so. They could not have known the 

 primary cause of the change of position of certain of their 

 fellows, nor could there have been any hope of seizing 

 the food, as that always fell to the fish nearest to whose 

 mouth it dropped. Then, in a third manner, I would 

 test the school by throwing a grasshopper some distance 

 behind the last of the fishes. The struggles of the insect 

 upon the surface would attract the hindmost roach in a 

 moment, and the fish would reverse its position. Quite 

 as promptly, the foremost fish would turn about in like 

 manner. It was evident, therefrom, that these fish are so 

 intimately associated as to act promptly as one body. 

 "What purpose does it serve ? So far as a food-supply is 

 concerned, it is disadvantageous, as the roach are carnivo- 

 rous, and no such abundance of insect or other animal 

 life is met with as to supply each member of a school 

 of two or three hundred individuals. This social instinct 

 would seem to have arisen as a means of protection. If 

 so, I am " at sea " as to what enemies they elude by as- 

 sociation. At present, the perch and pike prey upon 

 them, and the former follows the schools until surfeited 



