40 BIOGRAPHY. 



These men, by the way* used to be most determined 

 poachers, and, on account of their mode of life, even if 

 detected and chased, they could escape by means of their 

 barges. They were charv, however, of venturing inside a 

 sixteen feet wall, and after p while ceased from troubling. 

 Such a work was necessarily very expensive, costing at 

 least ten thousand pounds. It was too large a sum to be 

 paid at once, and Waterton would not run in debt. So, 

 every year, he put aside as much money as could be spared 

 for the wall, went on building until the money was ex- 

 pended, and then stopped the work, and waited until the 

 following year to continue it. The wall was three miles in 

 total length, and inclosed an area of two hundred and 

 fifty-nine acres. 



The value of this wall was shown by the fact that the 

 very year after it was finished the herons came and estab- 

 lished themselves within it. At my last visit in 1863, 

 there were nearly forty nests. 



How should they know that a wall could protect them 

 against man ? It was no obstacle to them, and how they 

 could have known, as they evidently did, that it was an 

 obstacle to mankind is one of the yet unsolved problems 

 which puzzle students of zoology. Moreover, they knew 

 that those few specimens of humanity who came within 

 the wall would do them no harm. I have often been in 

 the heronry, with the blue fragments of broken eggs lying 

 on the ground, and seen the herons going to and from their 

 home with perfect unconcern. Even on the ground, the 

 herons had no fear of man. Provided that a man ap- 

 proached them slowly and quietly, he could come close 

 enough to see their eyes, and even to notice the reflection 

 of the rippling water upon their grey plumage. 



Not only in the heronry, but in other parts of the park 

 near the water, the birds would allow themselves to be 



