134 ANIMAL FORMS 
parasites or as active predaceous animals upon other animals. 
For this purpose many are provided with keen senses for 
detecting their prey and poisonous spines for despatching it. 
129. The scorpions,—Owing to the stout investing armor, 
the strong pincers, and the general form of the body, the 
scorpions might at first sight be mistaken for near relatives 
of the crayfish or lobster. 
A more careful examina- 
tion will show that the 
two pairs of pincers prob- 
ably correspond to the 
antenne and mandibles of 
the Crustacea that have 
become modified for seiz- 
ing the food. The swol- 
len part of the animal 
lying behind the four 
pairs of legs is a part of 
the abdomen, of which 
the slender “tail” consti- 
tutes the remainder. On 
the tip of the tail is a 
curved spine supplied 
with poison glands. Sev- 
eral pairs of eyes are borne 
on the dorsal surface of 
the head and thorax, while 
on the under side of the animal several slit-like openings 
lead into as many small cavities containing the lung-books, 
The scorpions are the inhabitants of warm countries, 
where they may be found under sticks and stones through- 
out the day. At night they leave their homes in search of 
food, which consists chiefly of insects and spiders. These 
are seized by means of the pincers, and the sting is driven 
into them with speedily fatal results. It is doubtful if the 
poison causes death in man, but the sting of some of the 
Fic. 82.—Scorpion, showing pincer-like mouth- 
parts and spine-tipped tail. 
