POWER OF RECOGNITION AMONG ANTS. 2JI 



account of that colony. On July 28, 1903, this N colony of 

 Cainponotns pcnnsyhanicus was captured on Nonamesset Island, 

 and was housed in a large Fielde nest. It consisted of a queen 

 two centimeters long, some scores of workers, and numerous 

 cocoons. During the first week in August, 1903, the queen 

 deposited about one hundred eggs, and then ceased laying until 

 the following March. The first larva from the August eggs was 

 observed on August 27. From these larvae the first cocoon 

 appeared on March 13, 1904. On April 8, 1904, there were 

 many large larvae in the nest, and there were numerous cocoons 

 varying in length from five millimeters to thirteen millimeters. 

 The first cocoon of this brood hatched on April 24, the tem- 

 perature of the room being 24 C. or 76 F. These cocoons con- 

 tinued to hatch, most of them in carefully segregated groups, 

 until July 14, when the last cocoon rendered its callow. 



E.vperuncnt A. Three large workers hatched each in isolation 

 on July 8, 1 1 and 14, 1904, from the August eggs of the N queen. 

 On August 5, these three worker-ants, ranging from twenty-two 

 to twenty-eight days in age, and never having met any ant-queen, 

 nor any ant older than themselves, instantly affiliated with their 

 queen-mother, and with each other, at the first meeting. The 

 queen manifestly recognized the odor borne by the callows, and 

 at once snuggled with them. 1 They each recognized in her and 

 in each other the only ant-odor they had ever known, that of 

 their own bodies. 



Experiment B. Four N colony workers, the issue of eggs 

 deposited by the queen in August, 1903, were hatched from se- 

 gregated cocoons, between May 15 and June 15, 1904. On July 

 6, when the age of these ants ranged between twenty-one and 

 fifty-two days, and they had never met any other ant of their 

 species, I introduced their queen-mother to their nest. The five 

 immediately affiliated and the previously introduced larvae were 

 brought and placed beside the queen. The queen must have been 

 at least one year older'than these workers, and the workers must 

 have recognized in the queen their own odor at hatching time. 



Experiment C. Five Camponotus workers hatched between 



1 The behavior of the ants in these experiments was observed through an orange- 

 tinted roof-pane, under which the ants behave as if in darkness. See " Supple- 

 mentary Notes on an Ant," referred to in first foot-note. 



