SENSE OF DIRECTION IN WASPS. 419 



of direction in ants, concluded, after a number of 

 observations, that they were endowed with this sense 

 in a high degree. Subsequently he discovered, quite 

 accidentally, that the ants found their way by observ- 

 ing the direction in which the light was falling.' My 

 conclusion was, however, the result of many observa- 

 tions carried on under varied conditions, and I should 

 hardly call it an accident. 



They came to the conclusion, as I had done, that 

 wasps have no sense of direction, that is to say in the 

 form of a mysterious additional sense, but that, if they 

 do not know where they are, they rise higher and 

 higher into the air, circling as they do so, until they 

 discover some high treetop or other object that had 

 before served them as a landmark, and that in thia 

 way they are able to make their way home. This 

 entirely tallies with my own conclusion. It is interest- 

 ing as showing that the vision of wasps must be good 

 for somewhat distant objects. 



They also found, as I had done, that their memory 

 varied greatly in ditferent individuals. 



Domestic Economy of Ants. 



Lastly, I give two illustrations which will convej 

 an idea of some of my ant-nests. 



Plate VI. represents about a quarter of one of my 

 frames. The shaded part represents the earth, which 

 will be seen to have been arranged by the ants into a 

 sort of circular fortification, or zereba, access to which 

 is obtained by one or two tunnels, not visible in the 

 illustration, and to which a pathway leads from the 

 entrance. 



Plate VII. represents a nestofXasms niger. It shows 

 the entrance, vestibule, and two chambers, in the outer 

 and larger one of which the ants have left some pillars, 



B B 2 



