196 S. J. HOLMES. 



phipoda, although, as has been pointed out above, contact still 

 increases the duration of the feint. Contact, finally, may come 

 to be necessary only to set up the instinctive response, having 

 become entirely superfluous for its continuation. And if we 

 conceive the necessary stimulus to be reduced to a single tap 

 or even a jar we can understand how death-feigning reactions 

 such as are found in certain beetles where the response often fol- 

 lows upon the slightest disturbance may have been evolved. 

 Whether they have been so evolved is a question which it would 

 be rash with the evidence in hand to attempt to answer. The 

 singular circumstance that the death-feigning reaction is almost 

 always evoked in response to some form of contact stimulus 

 might be urged in support of such view. The instinct of feign- 

 ing death has been evolved independently so many times that it 

 is quite possible, if not probable, that it has risen by different 

 methods in different groups of animals. The problem can be 

 solved only by a careful comparative study of death-feigning in 

 several related forms among the various groups of the animal 

 kingdom in which the instinct occurs. 



