1901.] NATURAL SCIENCES OF PHILADELPHIA. 537 



many of its pupse. I then segregated all callows that appeared 

 on the same day among the pupre, and in my experiment used 

 none that had been nursed bv any ant during the last three days 

 of the pupa-stage, or that had ever met any ant other than those of 

 her own age and lineage. When the callows were from sixteen 

 to twenty days old, I introduced into a Petri cell containing several 

 of the segregated callows single ants from among their blood- 

 relations in the Lubbock nest. Ants of about their own age were 

 always received with little attention and no nabbing; older workers 

 with considerable attention and occasional nabbing; and very old 

 workers or queens were attacked and pulled about by as many as 

 three or four callows at once. The amount of excitement produced 

 by the newcomer, and the number of attacks made upon her 

 person, bore a direct ratio to the depth of her color. When an 

 old worker had first been introduced and domiciled, the introduc- 

 tion of a second adult caused little excitement ; but that of a queen 

 called forth all the usual demonstrations of interest or distrust. 

 If a queen was first introduced and domesticated, then the intro- 

 duction of an old worker was an unimportant event. A second 

 queen or a second adult was always received with lesser attention. 

 I therefore think that the ants discriminate not only in regard to 

 the quality of the odor presented, but also as to its intensity, and 

 that the queen presents the ancestral odor in a more concentrated 

 form than do her workers. None of these introduced ants 

 attacked the callows, and all callows affiliated with the introduced 

 ants within a day; but the fighting instinct of the callow is evi- 

 dently aroused, not only by ant-odors to which it is unaccustomed, 

 but by an intenser expression of its own inherent odor. If the 

 older ants bore an adventitious odor through association with aliens 

 reared in their nest, then the young ants would have borne the 

 same odor and would have offered the same reason for attack. 



With the purpose of ascertaining Avhether the odor of the ant 

 was perceptible to other ants when deposited upon inanimate objects, 

 I took a new unused maze and smeared the floor and walls of the 

 a and the n rung with the juices of kindred queens and workers, 

 and the in and b runs with the juices of aliens, leaving the c and 

 d runs unsmeared. This smearing did not manifestly influence the 

 ants in their choice of a route in carrying pupae from T to I. 



I then laid upon the floor of the a and n runs earth newly 



