453 



the trail, going over the edge to the lower surface, back through the 

 hole in the center, until she had completed the round more than a 

 dozen times. After that she seemed to realize that she was not get- 

 ting anywhere and began to wander about. 



CONCLUSIONS 



1. A trail once formed by Mononioriuni pharaonis is followed 

 regardless of any change made in its direction. 



2. Change in the direction from which the light comes does not 

 influence this species in following its trail. 



3. Ants of this species can recognize a trail laid down by other 

 individuals of the same or of a different colony. 



4. Monomorium pharaonis can still recognize a trail sufficiently 

 well to follow it, after it has ceased to be used for at least 26 hours 

 and 15 minutes. 



5. The behavior of ants of this species when placed upon the 

 trail seems to indicate that they do not recognize which direction leads 

 to the nest. 



I do not, of course, attempt to apply these conclusions to all ants, 

 for a study of the literature upon ants, or, better still, a study of 

 the various species of ants themselves, will soon convince one that 

 there is probably as much diversity in the habits of different species 

 of ants as there is in the habits of different species of mammals or 

 of birds. It is probable, however, that they may apply more or less 

 closely to those species of ants which have very small eyes and travel 

 in regular files. 



