f the black-billed. "We have them both," said the President, "but the
yellow-billed is the more common."

We continued our walk along a path that led down through a most
delightful wood to the bay. Everywhere the marks of the President's
axe were visible, as he had with his own hand thinned out and cleared
up a large section of the wood.

A few days previous he had seen some birds in a group of tulip-trees
near the edge of the woods facing the water; he thought they were
rose-breasted grosbeaks, but could not quite make them out. He had
hoped to find them there now, and we looked and listened for some
moments, but no birds appeared.

Then he led us to a little pond in the midst of the forest where the
night heron sometimes nested. A pair of them had nested there in a big
water maple the year before, but the crows had broken them up. As we
reached the spot the cry of the heron was heard over the tree-tops.
"That is its alarm note," said the President. I remarked that it was
much like the cry of the little green heron. "Yes, it is, but if we
wait here till the heron returns, and we are not discovered, you would
hear his other more characteristic call, a hoarse quawk."

Presently we moved on along another path through the woods toward the
house. A large, wide-spreading oak attracted my attention--a superb
tree.

"You see by the branching of that oak," said the President, "that when
it grew up this wood was an open field and maybe under the plough; it
is only in fields that oaks take that form." I knew it was true, but
my mind did not take in the fact when I first saw the tree. His mind
acts with wonderful swiftness and completeness, as I had abundant
proof that day.

[Illustration: A BIT OF WOODLAND ON THE SLOPE TOWARDS OYSTER
BAY

From stereograph, copyright 1907, by Underwood & Underwood,
New York]

As we walked along we discussed many questions, all bearing directly
or indirectly upon natural history. The conversation was perpetually
interrupted by some bird-note in the trees about us which we would
pause to identify--the President's ear, I thought, being the most
alert of the three. Continuing the talk, he dwelt upon the inaccuracy
of most persons' seeing, and upon the unreliability as natural history
of most of the stories told by guides and hunters. Sometimes writers
of repute were to be read with caution. He mentioned that excellent
hunting book of Colonel Dodge's, in which are described t