Carpenter-Ants. 303 



to depart from their accustomed manner, or from their not 

 observing in the extremities of their edifice the same 

 arrangement as in the centre : whatever it be, horizontal 

 stories and numerous partitions are still found. If the work 

 be less regular, it becomes more delicate; for the ants, 

 profiting by the hardness and solidity of the materials, give 

 to their building an extreme degree of lightness. I have 

 seen fragments of from eight to ten inches in length, and of 

 equal height, formed of wood as thin as paper, containing a 

 number of apartments, and presenting a most singular 

 appearance. At the entrance of these apartments, worked 

 out with so much care, are very considerable openings ; but 

 in place of chambers and extensive galleries, the layers of 

 the wood are hewn in arcades, allowing the ants a free 

 passage in every direction. These may be regarded as the 

 gates or vestibules conducting to the several lodges."* 



It is a singular circumstance in the structures of these 

 ants, that all the wood which they carve is tinged of a black 

 colour, as if it were smoked : and M. Huber was not a little 

 solicitous to discover whence this arose. It certainly does 

 not add to the beauty of their streets, which look as sombre 

 as the most smoke-dyed walls in the older lanes of the metro- 

 polis. M. Huber could not satisfy himself whether it was 

 caused by the exposure of the wood to the atmosphere, by 

 some emanation from the ants, or by the thin layers of wood 

 being acted upon or decomposed by the formic acid.f But 

 if any or all of these causes operated in blackening the wood, 

 we should be ready to anticipate a similar effect in the case 

 of other species of ants which inhabit trees ; yet the black 

 tint is only found in the excavations of the jet-ant. 



We are acquainted with several colonies of the jet-ants 

 (Formica fuliginosa) one of which, in the roots and trunk of 

 an oak on the road from Lewisham to Sydenham, near 

 Brockley, in Kent, is so extremely populous, that the 

 numbers of its inhabitants appeared to us beyond any 

 reasonable estimate. None of the other colonies of this 

 species which we have seen appear to contain many hundreds. 

 * Huber, p. 56. t The acid of ants. 



