"614 BECOED OF CUERENT EESEAECHES RELATING TO 



Btrangers, indicating, therefore, that the recognition is not effected 

 by means of any sign or password. 



With regard to workers breeding, the additional evidence tends to 

 confirm previously advanced views, that whefi workers lay eggs males 

 are always the issue of these. Without entering into details of 

 instances, it may broadly be affirmed that in the queenless nests males 

 have been produced, and in not a single case has a worker laid eggs 

 which have produced a female, either a queen or a worker. On the 

 contrary, in nests possessing a queen, workers have been abundantly 

 produced. The inference from these curious physiological facts leads 

 to the presumption that, as in the case of bees, so also in ants, some 

 special food is required to develop the female embryo into a queen. 



In Sir John's nests, while from accidents and other causes many 

 ants are lost during the summer months, in winter, nevertheless, 

 there are few deaths. As to the age attained, specimens of Formica 

 fiisca and F. sanguinea, still lively, are now four and others five years 

 old at least. 



The behaviour to strange queens often results in their being 

 ruthlessly killed ; yet as communities are known to have existed for 

 years, queens must cccasionally have been adopted. With the view 

 of trying how far dislike and passion might be assuaged by a formal 

 temjjorary acquaintance, a queen of F. fusca was introduced into a 

 queenless nest, but protected by a wire cage, and after some days the 

 latter removed, but the queen was at once attacked. Mr. McCook, 

 nevertheless, relates an instance of a fertile queen of Cremastogaster 

 lineolata having been adopted by a colony of the same species. Such 

 difference in conduct. Sir John suggests, may be due to his own ants 

 having been living in a republic ; for it is affirmed that bees long 

 without a queen are strongly averse to adoj)t or accept another. 

 Furthermore, if a few ants from a strange nest are put along with a 

 queen they do not attack her, and if other ants are by degrees added 

 tbe throne is ultimately secured. 



In pursuance of experiments to test the sense of direction, some 

 ants were trained to go for their food over a wooden bridge made up 

 of segments. Having got accustomed to the way, afterwards when 

 an ant was in the act of crossing, a segment was suddenly reversed in 

 direction, evidently to the ant's discomfiture ; she then either turned 

 round, or, after traversing the bridge, would return. When, how- 

 ever, similar pieces of wood were placed between nest and food, and 

 the ant at the middle piece, those at the ends being transposed, the 

 ant was not disconcerted. In other instances a circular pajier disk 

 was placed on a paper bridge, and when the ant was on the disk this 

 was revolved, but the ant turned round with the paper. A hat-box 

 with holes of entrance and exit pierced at opposite sides was planted 

 across the line to the food ; when the ant had entered and the box was 

 turned round, the ant likewise wheeled about, evidently retaining her 

 sense of direction. Again, with the insect en route- when the disk or 

 box with the ant within was merely shifted to the opposite side of the 

 food without being turned round, the ant did not turn round, but 

 continued in what ought to have been the direction to the food, and 



