70 BULLETIN OF THE ESSEX INSTITUTE. 



one time seen in conflict suorofested some other cause than 

 hostile colonies, or a struggle for booty. 



Contrary to the Missouri testimony, my pill-box mau- 

 soleum shows that the struggles were not uniformly be- 

 tween the large-headed and the small-headed ants. Often 

 two of the former or two of the latter are locked in the 

 final clasp. I could discover no rule of difference in size 

 or color. 



All these conflicts, I believe, began in the night — 

 usually, if not always, on sultry nights. There may be a 

 kind of craziness, a propensity to " run amuck," which at 

 times seizes a part or all of the workers of a formicary. 

 Some ants were generally recognized as friends, some as 

 enemies. Is it a witchcraft delusion ? 



My present residence was built in 1770 and early in 

 summer is seriously infested with these insects. Later 

 they are rarely seen in the house. Is it possible that these 

 battles are due to some Malthusian instinct by which, 

 when their services are no longer needed, the great mass 

 of the soldier and worker class slay one another and thus 

 empty the formicary that there may be room and welcome 

 for another generation ? Oris there a survival, in this 

 way, of the young and vigorous? Some of the questions 

 suggested can be finally answered only by the carefully 

 recorded observations of many independent and skilful 

 students of nature. 



