Instinct and its Lessons \ i T 



as his own, he constructs his fortress, thus described 

 by Mr. Bell: "The fortress is formed under a large 

 hillock. It contains a circular gallery within the base, 

 which communicates with a smaller one above by five 

 nearly equi-distant passages; and the domicile or chamber 

 is placed within the lower and beneath the upper cir- 

 cular gallery, to which it has access by three similar 

 passages. From the chamber extends another road, the 

 direction of which is at first downwards for several 

 inches ; it then rises to open into the high-road of the 

 encampment. From the external circular gallery open 

 about nine other passages, the orifices of which are 

 never found opposite to those which connect the inner 

 and upper gallery; these extend to a greater or less 

 distance, and return into the high-road at various dis- 

 tances from the fortress." 1 Thus the chamber commu- 

 nicates downwards directly with the higher road and 

 upwards with the upper gallery, which again commu- 

 nicates by five passages with the lower, and this again 

 with the road by no less than nine, affording an elaborate 

 system of escape. The high-road, so often mentioned, 

 extends from the fortress to the extremity of the domain, 

 and from it run on each side the alleys which lead to the 

 hunting-ground. The architectural craft of the Beaver 

 has been so often described that I need do no more than 

 allude to it in this connection. 



An instinct of quite another kind, but in which it is 

 equally difficult to trace a fortuitous origin, is that 

 exhibited by the Wild Duck in her efforts to decoy 

 an intruder from her young. So well is the game played 

 as to deceive a person who is familiar with it in books. 

 An angler, for instance, is wading up stream among the 

 hills, when suddenly, as he turns a corner, out flops from 

 under his feet a Duck, one wing dragging helpless, while 

 she impotently beats the water with the other. If young 

 and inexperienced, he will be sure, unthinkingly, to 

 make a dash at the bird which, flapping and quacking, 

 just out of his reach, leads him floundering on, and 

 1 British Quadrupeds, p. 93. 



