170 THEORETICAL BIOLOGY 



part in the sexual circle, and leads there to the ending of 

 copulation. This is seen most strikingly in the case of the 

 praying mantis. Here, as soon as the male has fecundated 

 her, the female proceeds to devour him. Immediately after 

 the male has disappeared as a sexual indication, the food- 

 circle comes in, and he now presents merely an indication 

 for prey. Many other insects behave in the same way ; the 

 females of spiders and of staphylinid beetles devour the 

 males when copulation is completed, and the males offer only 

 a feeble resistance, for the females never serve them as prey- 

 indication. 



Interesting though subjective annihilation of indications 

 is, we must omit it in dealing with the world of action, for in 

 that world only objective events take place. 



THE INDICATORS 



In considering all the various indications that surround an 

 animal, we perceive that the indicator towards which the 

 animal's action is directed, is very differently constructed 

 according to the particular inter-adjustment between it and 

 the animal. 



If in the enemy-circle a simple movement of flight follows 

 on a certain indication, whether that be of chemical, acoustic 

 or optical nature, the indicator is merely the bearer of the 

 property that is employed as indication by the fleeing subject. 



If, on the other hand, effectors come into action that serve 

 for defence, the indicator has a counter-framework which fits 

 in with the framework of these. Among such counter-frame- 

 works we may reckon those of the enemy's organs which 

 contribute towards his defeat. Thus, for instance, we may 

 reckon in the counter-framework of the sea-urchin, not 

 merely the external form of the star-fish's tube-feet, on which 

 the poison-pincers can lay hold, but also the nervous tissue 



