134 ANIMAL LIFE 
gulps air until its capacious stomach is filled, and then 
floats belly upward on the surface. It is thus protected 
from other fishes, though easily taken by man. The torpe- 
do, electric eel, electric cat-fish, and star-gazer, surprise and 
stagger their captors by 
— ae means of electric shocks. 
In the torpedo or electric 
ray (Fig. 70), found on 
the sandy shores of all 
warm seas, on either side 
of the head is a large 
honeycomb-like structure 
which yields a strong 
electric shock whenever 
the live fish is touched. 
This shock is felt severe- 
ly if the fish be stabbed 
with a knife or metallic 
spear. The electric eel 
of the rivers of Para- 
guay and southern Bra- 
zil is said to give severe 
shocks to herds of wild 
horses driven through 
the streams, and similar 
accounts are given of the 
electric cat-fish of the 
i Saar a Nile. 
Fig. 69.—Porcupine-fish (Diodon hystria), the . 
lower ones swimming normally, the upper Among the Insects, 
one floating belly upward, with inflated the possession of stings 
lig ita from specimens from the is not uncommon. The 
wasps and bees are fa- 
miliar examples of stinging insects, but many other kinds, 
less familiar, are similarly protected. All insects have 
their bodies covered with a coat of armor, composed of a 
horny substance called chitin. In some cases this chitin- 
