heritance, the fruition of ages, is somehow condensed;
but it is interesting to bear in mind the elementary fact that every
many-celled creature, reproduced in the ordinary way and not by budding
or the like, starts as a fertilised egg-cell. The coherence of the
daughter-cells into which the fertilised egg-cell divides is a
reminiscence, as it were, of the primeval coherence of daughter-units
that made the first body possible.

The Beginning of Sexual Reproduction

A freshwater Hydra, growing on the duckweed usually multiplies by
budding. It forms daughter-buds, living images of itself; a check comes
to nutrition and these daughter-buds go free. A big sea-anemone may
divide in two or more parts, which become separate animals. This is
asexual reproduction, which means that the multiplication takes place by
dividing into two or many portions, and not by liberating egg-cells and
sperm-cells. Among animals as among plants, asexual reproduction is very
common. But it has great disadvantages, for it is apt to be
physiologically expensive, and it is beset with difficulties when the
body shows great division of labour, and is very intimately bound into
unity. Thus, no one can think of a bee or a bird multiplying by division
or by budding. Moreover, if the body of the parent has suffered from
injury or deterioration, the result of this is bound to be handed on to
the next generation if asexual reproduction is the only method.

[Illustration: _Photos: J. J. Ward, F.E.S._

A PLANT-LIKE ANIMAL, OR ZOOPHYTE, CALLED OBELIA

Consisting of a colony of small polyps, whose stinging tentacles are
well shown greatly enlarged in the lower photograph.]

[Illustration: _Reproduced by permission of "The Quart. Journ. Mic.
Sci."_

TRYPANOSOMA GAMBIENSE

(Very highly magnified.)

The microscopic animal Trypanosome, which causes Sleeping Sickness. The
study of these organisms has of late years acquired an immense
importance on account of the widespread and dangerous maladies to which
some of them give rise. It lives in the blood of man, who is infected by
the bite of a Tse-tse fly which carries the parasite from some other
host.]

[Illustration: VOLVOX

The Volvox is found in some canals and the like. It is one of the first
animals to suggest the beginning of a body. It is a colony of a thousand
or even ten thousand cells, but they are all cells of one kind. In
_multicellular_ animals the cells are of _different_ kinds with
diffe