82 
LIFE AND HER CHILDREN. 
some crack in the rock in which to hide its soft 
body. 
These five animals the stone-lily, the brittle-star, 
the common star-fish, the sea-urchin, and the sea- 
cucumber, which grow up so curiously, each within 
an active feeding 
jelly being,* are 
thefive types of the 
"Prickly-skinned" 
animals t which 
form the third 
division of the 
animal kingdom ; 
and the history 
of their lives will 
give us a very fair 
idea of the imple- 
ments and wea- 
Infancy of a Sea-Cucumber. , . , , . 
pons used by this 
A, A jelly-animal swimming and feeding ; . . c 
a, small sea-cucumber forming inside. B, division, and OI 
The young sea-cucumber with the leaf-like the peculiar walk- 
tentacles round its mouth, walking on its . 
tube feet. in g apparatus 
which belongs al- 
most exclusively to this branch of life's children. 
Passing by, for a moment, forms I and 2, which 
we shall understand better presently, let us first visit 
the common star-fish after his arms are full grown, 
as we sometimes find him on the sand of the sea- 
shore thrown up by the waves. A strange and 
* The jelly animal does not always swim about in the water 
while forming its future body. Some star-fishes and sea-urchins carry 
their young in a kind of pouch or tent till they have taken shape. 
t Echinodermata, or hedgehog-skinned. 
