EXAMPLES OF INSTINCT 



knowledge of the meaning of the sow's grunting. 

 Spalding put a young pig into a bag the moment it 

 was born, kept it in the dark for seven hours, and 

 placed it near the sty, ten feet from where the sow 

 lay concealed. 



"The pig soon recognized the low grunting of its 

 mother, went along outside the sty, struggling to 

 get under or over the lower bar. At the end of 

 five minutes it succeeded in forcing itself through 

 under the bar at one of the few places where that 

 was possible. No sooner in, than it went without 

 a pause into the pig-house to its mother, and was 

 at once like the others in its behaviour." 



A blindfolded youngster found its mother almost 

 as well. as one with its eyes free. After two days' 

 blindfolding it required only ten minutes' practice 

 to make it " scarcely distinguishable from one that 

 had had sight all along." 



In the strict sense, birds do not learn to fly, though 

 their inborn capacity of flying is improved by 

 exercise. Spalding put five unfledged swallows in 

 a small box with a wire front, and hung it near the 

 nest. The parents fed the offspring through the 

 wires, and the young birds throve as usual, though 

 one was found dead just as it became fully fledged. 

 The others were set free one after another. Two 

 of them were perceptibly wavering and unsteady, 

 and two were more effective from the first. But 

 even the less endowed flew ninety yards right away, 

 and none of them knocked against anything. In a 

 subsequent experiment one of the newly-fledged, 

 newly-liberated birds performed almost at once 



113 H 



