384 'Journal of Cottrparative Nciii'ology and Psychology. 



for the first pupae to reach the nest in the second or third and most 

 of the subsequent experiments of a series, as contrasted with the 

 long time required in the opening experiment of that series, sug- 

 gests that the ants retain, for a while at least, what they have 

 acquired. Indeed, there is hardly an experiment recorded in this 

 paper, which does not indicate that ants profit by experience. 



That ants can be trained is further evidence that they retain for 

 a time what they acquire by experience. Ernst ('05) succeeded 

 in training a Formica fusca to feed from his moving finger. He 

 took a member of a colony of this species which had become some- 

 what famihar with man and confined it in a test-tube. In three 

 hours after being confined to the tube it would feel with its antennae 

 the finger of the operator when presented to the open end of the 

 test-tube. In order to tame it, food (honey, sugar) was oJfFered it 

 on the tip of the operator's finger, and in no other way. At the 

 close of a month the test-tube was left open. With keen attention 

 and with that tense attitude which would permit of immediate 

 flight, the ant approached the opening and felt exploringly with its 

 antennae. On the second day its conduct was similar; but on the 

 third day the ant wandered out for a distance of two centimeters. 

 At the close of the second month the ant would feed from Ernst's 

 finger, even when it was moving and the ant had to stretch half- 

 way out of the tube in order to do so. 



I have been able to train several ants to get to and from the 

 stage used in my experiments in extraordinary ways. Two of 

 these were trained to drop down; it might be nearer the truth to say 

 that they trained themselves to jump down. One of these ants 

 was a Myrmica punctiventris Rog. and the other was a Formica 

 fusca var. subsericea Say. In each case the trick was learned in 

 about the same way. A marked ant had been placed on the stage 

 with the pupae. Picking up a pupa it moved about at random 

 and accidentally fell off the stage. Its impetuous dash was what 

 carried Formica overboard; it is not possible to say what caused 

 the fall of the more slowly moving Myrmica. Although the verti- 

 cal distance from the stage to the island was four inches, the ant 

 neither dropped the pupa nor seemed the least disturbed by the 

 jar. It went at once to the nest, deposited the pupa and returned 

 to the island, where it meandered from place to place, evidently 

 not knowing how to return to the stage. With a pair of small for- 

 ceps I picked it up gently and replaced it on the stage. It picked 



