LIFE'S SIMPLEST CHILDREN. 
Fig. 7. 
that we can only glance at those minute specks of 
slime which build their skeletons of flint instead of lime. 
These animals are 
a little higher in 
the world than the 
lime - builders, for 
their body has with- 
in it a small bag or 
capsule, buried in 
the middle of the 
slime (see- Fig. 7), 
and in this bag 
the solid grains lie 
very thickly, and 
have sometimes 
small crystals a- 
mong them, while 
in the slime round 
it there are often 
little oil -globules floating. If you dip a glass 
into the quiet bays of Nice or Messina you may be 
fortunate enough to bring up one or more of these 
little sun-slimes, but they are so tiny and transparent 
that even when the light falls upon them you will 
only distinguish them as bright specks in the water. 
Their threads stick out stiff and straight, and for this 
reason they are all classed under the name Radiolaria, 
or ray-like animals. 
Let us look for a moment at Fig. 8, and study the 
solid skeletons which these Radiolaria build with the 
flint (or silex) which they find in minute quantities in 
the water. We saw that the lime-builders construct 
* Physematium. 
The Sun-Slime.* Haeckel. 
Immensely magnified, its real size being not 
larger than a mustard seed. 
