128 THE GKEEN WOODPECKER. 



three-quarters of an hour, succeeded in removing a wedge- 

 shaped slice, which contained, in its centre, the entrance 

 hole to the burrow. 



Why the bird should have selected a tree whose wood 

 w^as so hard, w^herein to excavate its home, was to me a 

 puzzle, as there were scores of others within a few hundred 

 yards of the spot showing marked signs of decay, whereas 

 this one appeared quite sound. Towards the end of last 

 year, however, I got a partial solution to the question, when 

 I visited the tree again, in order to submit it to a careful 

 examination. It was still apparently healthy, bearing 

 leaves and acorns, and this was five years after the nest 

 had been taken. Moreover, the bark had grown for some 

 distance over the spot where the wedge had been cut out, 

 thus proving the vitality of that part of tlie tree, at any 

 rate, through which the first part of the tunnel was bored. 

 Finding nothing amiss with the external aspect of the 

 oak, I climbed up in order to obtain a view of the interior, 

 through the opening made by the conjoint efforts of the 

 bird and the saw. On illuminating the burrow by means 

 of a match, I perceived that the posterior wall appeared 

 wet and partially decayed. 



This showed, what I had never suspected before, that 

 water must have gained access to the heart of the tree, and 

 had there been doing its slow, silent, but inevitably sure 

 work of destruction. The point at which the rain water 

 had first gained entry was not far to seek. A yard or 

 so above the burrow was a small dead branch, projecting 

 almost vertically upwards. The bark around the base of 

 this small branch formed a circular furrow, in which water 

 naturally found a lodgment, and, in course of time, pene- 

 trated to the centre of the tree, rendering that part con- 

 siderably softened. At this point the blade of a pen-knife 



