THE BABY SEA-URCHIN. 
81 
rosette. It went on growing for two or three years, 
lengthening the five knobs into pointed rays, and 
became the common Five-Fingered Star-fish. 
No. 4 took a different road from any of the three 
Fig. 34. 
that had gone before him. He 
too had long thin rods in his 
body, all pointing one way, 
so that his body looked like 
a painter's easel, and at the top 
of the easel a number of fine 
plates of lime began to form 
in the shape of a tiny round 
box (b, Fig. 34 A) with prickles 
all over it ; and by and by this 
box sucked up the jelly-body, 
leaving only a thin film over its 
shell, and sinking to the bottom 
a tiny Sea-Urchin, burrowed 
a hole for itself in the sand. 
Lastly, No. 5 did not form 
anything solid within its jelly- 
body, but growing a stomach 
and feet, and other soft parts, 
stretched itself out into the 
Shape Of a Sausage, put OUt . A, The jelly-animal with 
its lime-rods a a, swimming 
Some leaf-like tentacles round aDO ut and feeding while the 
its mouth (B, Fig. 35), and lay- tiny sea-urchin b, is forming 
, v ' JJ ' ' / r within it. B, The young sea- 
ing down some spikes of urc hj ni 
lime in its skin, became a 
little worm -like creature with tiny tubes for feet, 
the young of the Se a- Cucumber, \ and soon found 
Infancy of a Sea-Urchin. ' 
Muller. 
* Echinus. 
t Holothuriadae. 
G 
