vii DEFENCES OF INSECTS 269 



it an excellent object for imitation. Frequently the 

 peculiar protection of the mimicked species takes the 

 form of an excessive hardness, such as insectivorous 

 animals fail to crush or to eat. It is easy to under- 

 stand the benefit that comparatively soft-bodied and 

 eatable insects derive from fraudulent reproduction of 

 this indigestible characteristic. This is a defence 

 much mimicked by other, and often distantly related, 

 beetles. 



We come now to cases in which the affinity of the 

 resembling forms is more distant still, where the 

 mimicker is distinguished from the species that it 

 mimics by the wide differences that separate two 

 classes of a sub-section of the animal kingdom. Both 

 in the Old and the New World, spiders are known to 

 resemble ants. The deception is often most complete 

 as regards form and colour, and the habits of the 

 imitator carry out the dissimulation. One such 

 mimetic spider caught by Mr. Belt held up its fore- 

 legs to represent antennae, and they were used in the 

 characteristic manner. In Synageles picata and Syne- 

 mosyna formica (see Fig. 51) antennae are represented 

 by the second pair of legs. The walk and other move- 

 ments of many of these spiders correspond with those 

 of their models, and differ strangely from the motions of 

 their own allies. Elizabeth Peckham in describing S. 

 picata (see Fig. 50), an ant-like spider in North America, 

 states that " by far the most deceptive thing about it is 

 the way in which it moves. It does not jump like the 

 other Attidse, nor does it walk in a straight line, but 

 zig-zags continually from side to side, exactly like an 

 ant which is out in search of booty. . . . The ant 



