I96 JOHN L. PRICER. 



until they appeared, at first glance, much larger than those trav- 

 eling in the opposite direction. Thus, so far as this one colony 

 is concerned, the food was gathered almost entirely by workers 

 of these two intermediate sizes ; the one, no. 3, so far as I have 

 observed, without exception, first gathering the fluid from the 

 aphids, and no. 2 principally transporting it to the nest, though 

 aided by some of no. 3. 



I have not observed other colonies sufficiently to determine 

 whether this practice is general among them, though it surely 

 cannot be universal for many colonies find their aphids on the 

 same tree in which they live. This was a mature colony of large 

 size and had probably perfected this division of labor gradually 

 as the colony developed in conformity to the conditions that sur- 

 rounded them. 



The work of the two extreme sizes is more difficult to make 

 out, for they are in some way the " house-keepers," that is, they 

 are, during the daytime, at least, about the nest. The smaller 

 ones, size no. 4, are often seen carrying the particles of wood 

 and the empty pupa cases from the nest. Taking into account 

 the immense mandibles of size no. 1, one might suppose that these 

 are the true carpenter ants, and that it is their business to build 

 additions to the formicary ; but as has been shown in the tables 

 above, they appear in the colony after it is pretty well established, 

 and then occur in rather small numbers we must at least conclude 

 that they are not the only carpenters in the colony. In general 

 behavior they resemble very much the virgin queens. In the 

 artificial nest they remain constantly in the dark room, and when 

 the colored glass is removed they are among the first to seek 

 shelter and the last to show fight. I have had since capture 

 colony 6, Table III., in a nest which is connected with a feeding- 

 room by means of four glass tubes each about three and a half 

 feet long, three of them coiled and one straight, and I have never 

 seen a no. 1, in the feeding-room, although there are fifty of them 

 in the colony. The queen of this colony died soon after capture, 

 and yet many eggs have been laid, I consequently feel quite cer- 

 tain that the no. i's are principally egg-layers, and it is probable 

 that along with the development of the ovaries some of the 

 instincts of the queen also appear, and a corresponding lack of 

 certain other instincts possessed by the common workers. 



