o a living reality. It is a community in which already, low as it
is, the work of life has come to be discharged by distinct and fairly
specialized beings.

The era of new sponge-life is inaugurated by means of egg-development,
although there exists another fashion (that of gemmules or buds)
whereby out of the parental substance young sponges are produced. A
sponge-egg develops, as do all eggs, in a definite cycle. It undergoes
division (Fig. 1); its one cell becomes many; and its many cells
arrange themselves first of all into a cup-like form (5, 6 and 7),
which may remain in this shape if the sponge is a simple one, or
become developed into the more complex shape of the sponges we know.

In every museum you may see specimens of a beautiful vase-like
structure seemingly made of spun-glass. This is a flinty sponge, the
"Venus flower-basket," whose presence in the sponge family redeems it
from the charge that it contains no things of beauty whatever. So,
too, the rocks are full of fossil-sponges, many of quaint form. Our
piece of sponge, as we may understand, has yet other bits of history
attached to it.... Meanwhile, think over the sponge and its ways, and
learn from it that out of the dry things of life, science weaves many
a fairy tale.

[Illustration]

THE GREATEST SEA-WAVE EVER KNOWN

(FROM LIGHT SCIENCE IN LEISURE HOURS.)

BY R.A. PROCTOR.

[Illustration]

August 13th, 1868, one of the most terrible calamities which has ever
visited a people befell the unfortunate inhabitants of Peru. In that
land earthquakes are nearly as common as rain storms are with us; and
shocks by which whole cities are changed into a heap of ruins are by
no means infrequent. Yet even in Peru, "the land of earthquakes," as
Humboldt has termed it, no such catastrophe as that of August, 1868,
had occurred within the memory of man. It was not one city which was
laid in ruins, but a whole empire. Those who perished were counted by
tens of thousands, while the property destroyed by the earthquake was
valued at millions of pounds sterling.

Although so many months have passed since this terrible calamity took
place, scientific men have been busily engaged, until quite recently,
in endeavoring to ascertain the real significance of the various
events which were observed during and after the occurrence of the
earthquake. The geographers of Germany have taken a special interest
in interpreting the evidence afforded by this great ma