Siiiiniiary. 331 



An attempt is made to apply this conclusion to the " warning coloration " 

 of conspicuous insects. Evidence is collated to show that vertebrate foes 

 arc able to discriminate between palatable and unpalatable insects without 

 the aid of a distinguishing conspicuousness. If such power of discrimina- 

 tion exists, then since unpalatability must have preceded conspicuousness in 

 insects, this conspicuousness can not have been initiated by selection. If it 

 began without the aid of selection it may well have continued to develop 

 without it. The conspicuousness of warningly colored insects is then at- 

 tributed to the avoidance of them by vertebrate foes at a time when they 

 were still relatively inconspicuous. This avoidance rendered protective incon- 

 spicuousness unnecessary to them, while the nature of their food rendered 

 aggressive inconspicuousness unnecessary. Their unpleasant attributes have 

 protected them from their enemies, as the reefs have protected the coral-reef 

 fish. Under this immunity from selection they have been free to develop 

 conspicuousness, which is therefore regarded as an expression of race ten- 

 dency, of internal forces, in the absence of selection. 



The theory of ivumtuity coloration is proposed as a substitute for the 

 theory of warning coloration and it is shown that it covers certain cases not 

 covered by the theory of warning coloration. Immunity coloration is de- 

 fined on page 316. 



