cause when digestive difficulties of this kind arise he
gets out of them by splitting himself in two; and then each half builds
itself up into a fresh creature, and you have two polypes where there
was previously one, and the bone which stuck in the way lying between
them! Not only can these creatures multiply in this fashion, but they
can multiply by buds. A bud will grow out of the side of the body (I am
not speaking of the common sea anemone, but of allied creatures) just
like the bud of a plant, and that will fashion itself into a creature
just like the parent. There are some of them in which these buds remain
connected together, and you will soon see what would be the result of
that. If I make a bud grow out here, and another on the opposite side,
and each fashions itself into a new polype, the practical effect will be
that before long you will see a single polype converted into a sort of
tree or bush of polypes. And these will all remain associated together,
like a kind of co-operative store, which is a thing I believe you
understand very well here,--each mouth will help to feed the body and
each part of the body help to support the multifarious mouths. I think
that is as good an example of a zoological co-operative store as you can
well have. Such are these wonderful creatures. But they are capable not
only of multiplying in this way, but in other ways, by having a more
ordinary and regular kind of offspring. Little eggs are hatched and the
young are passed out by the way of the mouth, and they go swimming
about as little oval bodies covered with a very curious kind of hairlike
processes. Each of these processes is capable of striking water like an
oar; and the consequence is that the young creature is propelled through
the water. So that you have the young polype floating about in this
fashion, covered by its 'vibratile cilia', as these long filaments,
which are capable of vibration are termed. And thus, although the polype
itself may be a fixed creature unable to move about, it is able to
spread its offspring over great areas. For these creatures not only
propel themselves, but while swimming about in the sea for many hours,
or perhaps days, it will be obvious that they must be carried hither and
thither by the currents of the sea, which not unfrequently move at the
rate of one or two miles an hour. Thus, in the course of a few days,
the offspring of this stationary creature may be carried to a very great
distanc