its work about the size of a fist, takes no rest until it is
completed, and is able to finish it in five or six days. It is the
male alone who weaves this dwelling; when it is ready a female comes
to lay there, and generally fills it; it may contain from six hundred
to a thousand eggs.

[Illustration: FIG. 25.]

In the sea of Sargasso lives a fish which has received the name of the
_Antennarius marmoratus_. Its flattened and monstrous head gives it a
strange aspect, and it is marbled with brown and yellow. These colours
are those of the tufts of floating seaweed around it, and, thanks to
this arrangement, it can easily hide itself amid them without being
recognised from afar. This animal constructs for its offspring a
fairly safe retreat. The materials which it employs are tufts of
Sargasso so abundant in this portion of the Atlantic. It collects all
the filaments, and unites them solidly by surrounding them with
viscous mucus which it secretes and which hardens. When its work is
sufficiently firm not to be destroyed by the waves it lays its eggs in
it, and the floating nest is abandoned to its fate. The little ones
come out and find within it a sufficient protection for their early
age. These dwellings thus floating on the surface of the sea are
rounded and about the size of a cocoa-nut.

In Guiana and Brazil another species, the _Choestostomus pictus_, is
found, which is equally skilful. With aquatic plants it constructs a
spherical nest and arranges it in the midst of the reeds, level with
the water. At the lower part a hole is left, through which the female
comes to lay. After fertilisation, the couple, as is rarely found
among fish, remain in the neighbourhood of their offspring to assist
them if necessary. This praiseworthy sentiment is often the cause of
their ruin. The inhabitants of the banks speculate on the love of
these fish for their offspring to gain possession of them. It is
sufficient to place a basket near the entrance of the dwelling, which
is then lightly struck. The animal, threatened in its affections,
darts furiously forward with bristling spines and throws itself into
the trap.

It is scarcely necessary to recall the skilful art with which the
Stickleback which inhabits all our streams plaits its nest and remains
sentinel near it. (Fig. 26.) This fish has indeed monopolised our
admiration, and is considered as the most skilful, if not the only
aquatic architect. Yet, besides those which I ha