LENGTH OF LIFE. 9 



remain with comparatively little change throughout 

 the winter. It is much more difficult to ascertain the 

 length of life of the perfect insect, on account of their 

 gregarious habits, and the difficulty of recognising 

 individual ants. I have found, however, as we shall 

 presently see, that their life is much longer than has 

 been generally supposed. 



It is generally stated in entomological works that the 

 males of ants die almost immediately. No doubt this 

 is generally the case. At the same time, some males 

 of Myrmica ruginodis, which I isolated with their 

 mates in August T 876, lived until the following spring; 

 one of them till May 17. 



It has also been the general opinion that the 

 females lived about a year. Christ ' indeed thought 

 they might last three or even four seasons, but this 

 was merely a suggestion, and Forel expressed the 

 general opinion when he said, ' Je suis persuade qu'en 

 automne il ne reste presque plus que les ouvri^res 

 ^closes pendant le courant de I'^t^.' The average 

 life of a queen is also, he thinks, not more than twelve 

 months I have found, however, that the life of the 

 queens and workers is much longer than had been sup- 

 posed. I shall give further details in a subsequent 

 chapter, but I may just mention here that I kept 

 a queen of Formica fusca from December 1874 till 

 August 1888, when she must have been nearly fifteen 

 years old, and of course may have been more. She 



* Naturgesohichte der Insekten, 



