90 Bulletin American Museum of Natural History. [Vol. XXII, 



in order to rear a colony of loyal auxiliaries ; it being well known that 

 ants hatched in the presence of adult individuals of another species 

 are less liable to attack these even when they are recognized as 

 aliens. 



Of the rather numerous species of the rufa and exsecta groups, 

 F. consocians has furnished us with the clearest case of temporary 

 social parasitism through the immediate adoption of the fertilized 

 female by incerta workers. Not only is the consocians female apt to 

 arouse little or no hostility in the incerta, but she displays in her own 

 behavior a pronounced instinctive adaptation to an inquilinous or par- 

 asitic mode of life. When placed in an empty chamber communicating 

 with one occupied by incerta workers and their brood, she does not 

 hesitate to enter and approach the workers with fearless and con- 

 ciliatory gestures. She at once manifests a keen interest in the 

 persons of the workers and their callows, and if driven away or per- 

 secuted returns again and again without signs of fear or resentment. 

 Her attitude throughout is consistently insinuating. She licks the 

 workers continually and effusively, and, at least till she has been de- 

 finitively adopted, will even deign to feed them from her own crop. 

 Her behavior is often surprisingly like that of the workers of Lepto- 

 thorax emersoni, a highly inquilinous ant described in two of my 

 former papers. ^ 



This unusual behavior of the consocians queen endows some of her 

 physical characters, which would otherwise be difficult of explanation, 

 with a peculiar significance. I allude especially to her diminutive 

 stature and uniform yellow coloration. Both of these peculiarities 

 may be mimetic, since they must enchance her resemblance to the 

 incerta workers, and may therefore facilitate an alliance between the 

 two species. The fulvous yellow hairs on the body of the consocians 

 female are also suggestive of myrmecophily, since it is known that 

 many myrmecophilous arthropods, especially beetles, belonging to 

 the most diverse taxonomic groups, present a peculiar convergent 

 character in the form of tufts of yellow hairs connected with osma- 

 teria. These hairs are licked by the ants with unmistakable signs of 

 satisfaction. 



It is probable that the diminutive stature, though it may be re- 

 garded as a mimetic character, has not been developed as such, but is 

 rather a result of precocious development. This, in turn, must be 

 due to underfeeding during the larval stages. I have shown (p. 50) 



' The Compound and Mixed Nests of American Ants. Am. Natur,, XXXV, igoi, p. 431 et seq.: 

 and Ethological Observations on an American Ant (Leptothorax emersoni Wheeler). Archiv £. 

 Psychol u. Neurol., II, 1003, pp. 1-31. 



