60 
ANIMAL LIFE ON THE 
next morning they were as active as ever, and continued so 
for four days ; on the fifth morning, however, all was still. 
The oosing out process at the broken edges of the skin was 
too much for the over-wrought pedicellarise, and the 
consequence was exhaustion and death. 
In the third place. What is the work of the spines ? 
First, let it be explained that the spines and shell are of a 
very porous nature. If a mouthful of water be taken, and 
the shell held to the lips, every drop of the water can be 
easily blown into it. 
Well, then, the skin, being the absorber only of the 
nervous matter brought down to it by the pedicellariae, 
cannot retain the lime of that substance, which, still in a 
fluid state, must also find a store-house, which is readily 
found between the skin and the socket or basin of the 
spines in each segment where it continually accumulates ; 
and as the spines revolve in their circuit, acting also like 
the force-pump of the pedicellarise, the fluid, with its lime 
deposit, is forced with an equal pressure on all sides up the 
spine and into the segment, which retain the lime and 
allows the water to flow inward, which accounts for the 
large quantity of sea water always found in the interior of 
the urchin. 
This theory seems to me to be more in keeping with 
the fixed laws of nature. The skin of the human being has 
its particular functions to perform ; and we know that the 
heart, acting like a force pump, sends the blood to the 
extremities, and conveys to even the nails of the toes and 
fingers the substance for building them up. 
THE YOUNG SPINES. 
Nevertheless the formidable appearance of the spines, 
they are indeed tender members. Even after a careful 
