368 PHYLUM ARTHROPODA. 
bends down on the basal joint in ‘‘sub-chelate” fashion, and is per- 
forated by the duct of a poison gland. 
2. The leg-like, usually six-jointed, non-chelate pedipalps, whose 
basal joint helps in mastication, while the terminal joint in the male 
expands as a reservoir for the spermatozoa and serves as a copulatory 
organ. 
ae Four pairs of terminally clawed 7-jointed walking legs. The 
most anterior pair are much used as feelers. The spinnerets at the 
end of the abdomen are modified abdominal legs. Besides these the 
embryo has four pairs of abdominal appendages which abort. 
Fic. 192,—Garden spider. 
I., Female garden spider; II., end view of head of the same 
showing the simple eyes, the poison fangs (ch.), and the 
pedipalps (A.); III., pe end of body showing two pairs 
of spinnerets (s#.), with anus above. 
The nervous system is of the usual Arthropod type, but 
shows much centralisation. Thus the ventral ganglia are 
fused into one large centre in the cephalothorax (see Fig. 
193), a condition comparable to that in crabs. There 
are two or three rows of simple eyes on the cephalothorax, 
whose focal distance is very short, spiders trusting most 
to their exquisite sense of touch, by which they discriminate 
