IN DEFENSIVE COLORATION 325 



a reserve of defence. Furthermore, the poison does not 

 cause immediate death, and the enemy would have time 

 to injure or destroy the snake. 



II. Directive Marks and StrtuttLres. — Another Apo- 

 sematic use is of a different kind, viz. to divert attention 

 from the vital parts and thus give the animal attacked an 

 extra chance of escape. The large, conspicuous, easily- 

 torn wings of butterflies and moths act in this way, as is 

 shown by the numbers of individuals which may be 

 captured with notches bitten symmetrically out of both 

 wings when they were in contact. The eye-spots and 

 ' tails ' so common on the hinder part of the hind wing, 

 and the conspicuous apex so frequently seen on the fore 

 wing, probably have this meaning. Their position cor- 

 responds to the parts which are most often found to be 

 notched in fresh specimens. In some cases (e. g. many 

 Lycaenidae) the ' tail ' and eye-spot combine to suggest 

 the appearance of a head with antennae at the posterior 

 end of the butterfly, the deception being aided by move- 

 ments of the hind wings.^ It has already been pointed 

 out on p. 303, that the brightly coloured hind wings of 

 certain moths and grasshoppers are of benefit in the 

 manner here described. 



The flat-topped ' tussocks ' of hair on many caterpillars 

 look like conspicuous fleshy projections of the body, and 

 they are held prominently when the larva is attacked. 

 If seized, the ' tussock ' comes out, and the enemy is 

 greatly inconvenienced by the fine branched hairs. The 

 tails of lizards, which easily break off, are to be similarly 

 explained, the attention of the pursuer being probably 

 still further diverted by the extremely active movements 

 of the amputated member. Certain crabs similarly throw 

 off their claws when attacked, and the claws continue to 

 snap most actively. The tail of the dormouse, which 

 easily comes off, and the extremely bushy tail of the 

 squirrel, are probably of use in the same manner. 



The classification of Directive Characters is a matter of 



^ This deeply-interesting adaptation has been independently recognized 

 by many naturalists in many countries. P'or a list of records see Proc, 

 Ent. Soc, Lond.y 1906, p. lii ; also Ent. Mo. Mag.^ 1906, p. 128. 



