BY HENRY TRYON. 151 
America, and the habit is not necessarily restricted to ants of a 
tropical climate. They all belong to one sub-family of the Formz- 
cide, viz., the Myrmicide—ants endowed with a sting, and which 
have two joints in the peduncle connecting the thorax with the 
abdomen; but they are by no means limited to a single genus, 
or to genera closely allied. The genera including species of 
harvesting ants are Atta, Myrmica, Pheidole, Pogonomyrmex, 
Gicodoma, Pseudomyrma, and Meranoplus. All of these are 
morphologically speaking very distinct, and do not comprise 
species alone, in which this habit is predominant. 
It will be readily understood then that, in so much as there is 
no characteristic structural feature by which this class of ants is 
distinguished, the peculiar habit of harvesting grain is not due 
to any special organization, but that it is rather the result of 
inherited experience—or what used to be called instinct—of the 
necessity of some such provision by reason of conditions acting 
from without; and a certain plasticity in the ant organization is 
all that need be taken into account in considerations relating to 
the adaptability of these ants, and this is often very noticeable, 
to fulfil the conditions which the possession of the peculiar 
trait has imposed upon them. 
Scarcely any record of the occurrence of this habit amongst 
Australian ants is to be met with, though such a feature could 
not have escaped the observation of Mr. Damel, who, in the 
interests of the Godeffroy Museum, gave such assiduous attention 
to collecting the ants of Australia, and of Queensland in par- 
ticular. 
The first intimation of the existence of harvesting ants in 
Australia seems to have been made by Mr. W. E. Armit, F.L.S., 
in the following letter dated from Dunrobin, Georgetown, L9th 
July, 1878, and addressed to the Editor of ‘‘ Nature ’:— 
that Formica braunea is one of the species of ants which not unfrequently 
causes great loss to the farmers by purloining his seed when sown broad- 
cast. {Morton’s Cyclopedia of Agriculture, 1855, p. 918.] That these 
seeds are also harvested may be regarded as at least very probable. 
