FISHES. 
43 
William, “ and it was not easy to pick up tlie fishes 
we caught, because they slipped out of our hands. 
Why are they so slippery?” 
“ They are able to send out a kind of slime over 
their scales,” said Mr. Johnson, “and, as you may 
suppose, this helps them to pass easily through the 
water.” 
FISHES.— II. 
1. “If you watch the gold-fishes in the globe you 
will be able to find out how they drive themselves 
along,” said Mr. Johnson. 
2. “ Notice the two pairs of small fins at the sides. 
Along the middle of the back, as well as under the 
The Eel. 
body, you see other fins, which help to balance the 
fish and keep it upright. For small movements 
the fish uses its paired fins, but to drive itself 
swiftly forward it sweeps its large tail-fin from side 
to side. The fins do not have the same shape in 
