female lobster carries the eggs in this way, aerating them all the time
with the movement of the swimmerets. When they are caught in the
lobster-pots in the months of June and July, the eggs are taken to the
hatchery, and the ova are detached. As they are already fertilised, they
are put into hatching jars, where in due course they become young
lobsters, or rather lobster larvae, for the lobster does not start in life
quite so much developed as does the infant crayfish. It is about one-third
of an inch long, has no large claws, and swims naturally on the surface of
the water, instead of lurking at the bottom as it does when it has come to
lobster's estate. It seems to be compelled to rise to the surface, for
sunlight, or any bright illumination, always brings swarms of lobsterlings
to the top of the jars in which they are hatched. In the sea this impulse
towards the light stands them in good stead, for in the surface-waters
they find themselves surrounded by the countless atoms of animal life, or
potential life, the eggs and young of smaller sea beasts. The young
lobster is furiously hungry and voracious, because, like the young
crayfish, it has to change not only its shell but the lining of its
stomach five times in eighteen days. Unfortunately, in the hatching jars
there is no such store of natural food as in the sea. The result is that
the young lobsters have to eat each other, which they do with a cheerful
mind, if they are not at once liberated. When they have reached their
fifth month they go to the bottom and "settle down" in the literal sense
to the serious life of lobsters.

[Illustration: A TROUT. _From a photograph by Charles Reid._]

I believe no one ever saw trout spawning in the Thames, though there are
plenty of shallows where they might do so. Consequently the Thames trout
must be regarded as a fish which was born in the tributaries and descended
into the big river, and as the mouths of these trout-holding tributaries,