Systematic Course, 11 
most spiders feed. The second cepbalic appendage has 
a large, jointed palp (pedi palpus), which often has the 
appearance of a fifth leg. The order comprises a large 
number of groups of species which catch their prey in 
a variety of different ways. From an Indian forester’s 
point of view the Araneida are of no very great im- 
portance. The students should examine and sketch a 
few typical representatives from the Museum, 
The Scorpiontdea (Scorpions) are characterised by a pecu- 
liar elongated segmented abdomen, the posterior portion 
of which is modified into a long tuil-like appendage 
terminating in a large poison spine. The second pair of 
cephalic appendages (pedipalpi) are armed with large 
and powerful pincers (chelz). Scorpions feed chiefly 
on spiders and insects, which they are said to catch with 
their chele and sting to death with their caudal poison 
spine. The sting of large individuals is said to be 
powerful enough to be of serious nature even to man, 
The students should examine and sketch a scorpion 
making out the features noticed above. 
(¢) Insecta.—The Insecta (Insects) are characterised by the pos- 
session of three pairs of jointed legs. They generally have 
the body divided into the three well-marked regions of head, 
thorax and abdomen. For accounts of the structure of 
typical insects, see the chapters on the dissection of the 
cockroach and the mulberry silk-worm. Insects comprise 
some hundreds of thousands of species many of which are 
of very great importance in Indian forests. It will there- 
fore be necessary to consider the chief ‘sections of the group 
in detail, 
