g almost entirely of the nucleus of the cell and
carrying the determinants which were to decide one-half of its future
characters, penetrated this egg and fused with its nucleus. This was
filled with the determinants of the characters inherited from the
mother. Of course many of the eggs, of which probably there are a
thousand, must have escaped fertilization. There are doubtless a
thousand sperm cells that went to utter waste for one which found an
egg to fertilize. These eggs nestled in the crevices between the
stones in the warm water of the edge of the lake. Here the sun could
easily penetrate to the bottom and hatch them. The little fish, still
guarded by one hovering parent, swam around in the water long before
the yolk of the egg, containing its large amount of food, had been
absorbed into the tissues of the young fish. This fatty store made the
abdomen of the fish in which it lay protrude enormously. Gradually the
fish grew larger and the yolk grew smaller until all had been
consumed. Soon the fish began to forage for himself and no longer to
demand or care for the company and protection of its parent. The
little sunfish is highly favored among his comrades in having any care
whatever by the parent. In the case of most fishes the female,
swimming slowly over the bottom, deposits her eggs, which are
fertilized by the male, which follows behind her. After the eggs have
thus been laid and quickened no other attention is paid to them by
either of the parents.

Fish are stupid almost beyond the comprehension of those who are not
students of the minds of animals. Frogs and toads are a distinct step
in advance, and hence their mental activities play a larger part in
the process.

In the love-making of the frogs and toads the song has an important
share. In each species the voice is a little different from that of
any other. In our familiar garden toad we have an excellent
illustration of the method common to the entire group. When spring
comes an impulse seems to stir in all the toads of a neighborhood.
Heretofore they have stuck faithfully to dry ground; now they start
off for the water. Whether their impulse is simply to move down hill
or whether they by some means detect the near presence of water, I
cannot say. Certainly a new fountain on a lawn will secure in spring
its prompt and full share of the neighborhood's toads. In any event
the toads of a district congregate in great numbers in any pond or
along the ed