256 THE COLOURS OF ANIMALS 



attack, are very bold and fearless, so that no disguise 

 is necessary in order to approach them. The spiders, 

 on the other hand, are eagerly sought for by insecti- 

 vorous birds; hence there is little doubt that the 

 mimicry is protective.^ 



E. G. Peckham also describes two ant-like spiders 

 in North America. Synageles picata (see fig. 53) is 

 like an ant in form and colour ; 

 but ' by far the most deceptive 

 thing about it is the way in 

 which it moves. It does not 

 jump like the other Attidce, nor 

 „ „ ^ , . , does it walk in a straight line, 



Fig. 53.—SynacfeIes picata ; an o » 



an^uke spider (from Peck- ^^^ zigzags contiuually from side 

 to side, exactly like an ant which 

 is out in search of booty. . . . The ant only moves 

 in this way when it is hunting, at other times it goes 

 in a straight line ; but its little imitator zigzags always.' 

 Unlike Mr. Belt's spider, S. picata holds up its second 

 pair of legs to represent antennae. ' Spiders commonly 

 remain nearly motionless while they are eating ; picata, 

 on the other hand, acts Uke an ant which is engaged in 

 pulling some treasure-trove into pieces convenient for 

 carrying. I have noticed a female picata which, after 

 getting possession of a gnat, kept beating it with her 

 front legs as she ate, pulHng it about in different 

 directions, and all the time twitching her ant-like 

 abdomen.' This spider certainly does not molest the 



' Loc. ciU pp. 314, 315. 



