1901,] NATURAL SCIENCES OF PHILADELPHIA. 449 



the two parties I secured the safety of both for eight days. When 

 I put in larvaB there was strife for its possession, and at the end of 

 tl|iree weeks the only survivor of one party defended the larvai 

 against the sole survivor of the other party that, with but five 

 legs and a single antenna, still made stealthy approaches toward 

 the coveted young. 



My observations of Stenamma Julvum piceum sustain the usual 

 view that ants have an inherent and hereditary odor, or something 

 akin to odor, whereby they are identified as friends or enemies, and 

 that they impart this odor to places which they frequent. All the 

 phenomena that I have observed in the lives of Stenamma Julvum 

 piceum indicate that the distinctive odor may appear first in the 

 larvoe, and a little less faintly in the pupre; that it intensifies with 

 age as does the color; that the sensitivity of the queen to this odor 

 is greater than is that of the workers; that any distinctive odor 

 to wliich an ant is accustomed and with which it associates secu- 

 rity and satisfaction is attractive to it, while ant-odors to which it 

 is unaccustomed excite alarm and hostility in proportion to their 

 strangeness. For such causes, ants that have come from the eggs 

 of colony M and in their pupa-stage were transferred to colony N, 

 while they affiliate perfectly with the iVants that they live among, 

 quickly recognize the odor of the M ants because it is their own. 

 As to the origin of the distinctive colony odor, it appears possi- 

 ble that it may be traced to a king. 



Among Stenamma Julvum j^i^eum there are difiereuces in indi- 

 vidual traits. Some are more truculent than are others of their 

 sex, age and size; or are more assiduous in their attention to the 

 young; or more devoted to the queen or the males; or more grega- 

 rious in habit; or more attached to the home ; or more hostile toward 

 aliens. Every characteristic of a typical Stenamma Julvum piceum 

 appears strongly in certain individuals and is comparatively weak 

 in others. 



The increasing tameness of my captive ants has been observable. 

 After some months of acquaintance, these ^Nlyrmicid ants have 

 wholly ceased to sting me when I handle them. 



So domesticated have they become in their artificial nests that 

 they rarely run outside their houses w'hen uncovered, and the 

 accustomed routine of cleaning their dwellings agitates them 

 scarcely at all. 

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