ion (fig. 5) you will see a branch of one of these
colonies as it appears when highly magnified. Some of the animals you
will note are fully expanded, while others have partly withdrawn
themselves into their cups, which are here very small, though in some
species they are quite large. A little closer study of this magnified
portion of a branch will show you, here and there, little bud-like
bodies like unopened flower buds, attached by a short stalk. One of
these you will notice is more developed, and resembles a tree
('jelly-fish,' in fig. 5). If you could only watch it in the living
colony you would find that one fine day it broke off from its stalk, and
sailed away--jelly-fish, such as you see in fig. 3.

[Illustration: JELLY-FISH AFTER LEAVING THE COLONY Fig. 3.]

Probably all of you have found the empty shells of these wonderful
animal-trees dozens and dozens of times on the beach, and many of you
will find them in your collections of sea-weeds brought home as
treasures to remind you of the summer holidays. The so-called sea-fir is
all that is left of such a colony: the little tree-like tufts which you
doubtless found attached to rocks and stones represent other forms. Of
course, some of your sea-weeds are really what they appear to be--that
is to say, they are true plants; but those of which I speak now, though
they have a superficial resemblance to plants, are really animals. In
fig. 1 you will see some of the commoner forms of these strange animals
as they appear in life.

These colonies furnish us with an interesting illustration of the
division of labour, for, as you see, they are formed of two very
distinct kinds of individuals. The most numerous of these, those with
the long arms, have to capture and digest the food for the whole
community, including the little buds and bell-like individuals, for they
are mouthless. Their life of work begins, however, after they blossom
into jelly-fish, and they have a very important duty to perform. With
the great wide sea for a playground, they wander for a time at will,
warmed by the glorious sun, feeding on the delicious meats to be found
at the surface, for which their humble sisters at home must stretch
their arms in vain. And so they wander, far from the place which gave
them birth, growing bigger and stronger, finally fulfilling the task
which they were sent out to perform--the production of eggs from which
new colonies are to be started. These eggs grow into a litt