siting their eggs; as, when hatched in such a place, the young
will be comparatively free from the attacks of the larger carnivorous
forms. Among the lowest vertebrate often found in numbers in early
spring in these meadow rills and brooks is the lamprey, _Ammocoetes
branchialis_ (L.), or "lamper eel," as it is sometimes called. It has
a slender eel-like body, of a uniform leaden or blackish color, and
with seven purse-shaped gill openings on each side. The mouth is
fitted for sucking rather than biting, and with it they attach
themselves to the bodies of fishes and feed on their flesh, which they
scrape off with their rasp-like teeth. Later in the season they
disappear from these smaller streams, probably returning in midsummer
to deeper water. Thoreau, who studied their habits closely, says of
them: "They are rarely seen on their way down stream, and it is
thought by fishermen that they never return, but waste away and die,
clinging to rocks and stumps of trees for an indefinite period; a
tragic feature to the scenery of the river bottoms worthy to be
remembered with Shakespeare's description of the sea floor."

[Illustration: A LAMPREY.]

A few of the fishes, as the mud minnow and smaller catfishes,
together with most frogs, turtles, and salamanders, on the approach of
winter, burrow into the mud at the bottom of the streams and ponds, or
beneath logs near their margins. There they live without moving about
and with all the vital processes in a partially dormant condition,
thus needing little if any food.

The box tortoise or "dry land terrapin," the common toad, and some
salamanders burrow into the dry earth, usually going deep enough to
escape frost; while snakes seek some crevice in the rocks or hole in
the ground where they coil themselves together, oftentimes in vast
numbers, and prepare for their winter's sleep. In an open winter this
hibernation is often interrupted, the animal emerging from its retreat
and seeking its usual summer haunts as though spring had come again.
Thus I have, on one occasion, seen a soft-shelled turtle moving
gracefully over the bottom of a stream on a day in late December, and
have in mid-January captured snakes and salamanders from beneath a
pile of drift-wood, where they had taken temporary refuge.

[Illustration: TURTLE.]

With frogs, especially, this hibernation is not a perfect one, and
there is a doubt if in a mild winter some species hibernate at all.
For example, the lit