342 RECOGNITION OF FRIENDS AFTER A 



The difference of behaviour to friends and strangers 

 was therefore most marked. 



The friends were gradually licked clean, and except 

 for a few moments, and that probably by mistake, 

 never attacked. The strangers, on the contrary, were 

 not cleaned, were at once seized, were dragged about 

 for hours with only a few minutes' interval, by one, two, 

 or three assailants. 



Though the above experiment seemed to me con- 

 clusive, 1 thought it would be well to repeat it with 

 another nest. 



I therefore separated a nest of Formica fusca into 

 two portions on October 20, 1876. 



On P^'ebruary 25, 1877, at 8 a.m. I put an ant from 

 the smaller lot back among her old companions. At 

 8.30 she was quite comfortably established among them. 

 At 9 ditto, at 12 ditto, and at 4 ditto. 



June 8. — I put two specimens from the smaller lot 

 back as before among their old friends. At 1 they were 

 all right and among the others. At 2 ditto. After this 

 I could not distinguish them amongst the rest; but they 

 were certainly not attacked. 



June 9. — Put in two more at the same hour. Uj) 

 to 3 in the afternoon they were neither of them attacked. 

 On the contrary, two strangers from different nests, 

 which I introduced at the same time, were both very 

 soon attacked. 



July 14. — I put in two more of the friends at 10.15. 

 In a few minutes they joined the others, and seemed 

 quite at home. At 11 they were among the others 

 At 12 ditto, and at 1 ditto. 



July 21. — At 10.15 I put in two more of the 

 old friends. At 10.30 I looked ; neither was being 

 attacked. At 11 ditto, 12 ditto, 2 ditto, 4 ditto, and 

 6 ditto. 



October 7. — At 9.30 I put in two, and watched 

 them carefully till 1. They joined the other ants and 



