484 ants' nests. 



sages. I coujecture that the same thing is true of the various species 

 of the genus Leptogenys^ and that they use their long, thin, pointed, 

 sickle-sliaped jaws, which bear a strong resemblance to a curved 

 needle, to i^ierce the termites, whicli they then devour by the aid of 

 their comparatively powerful under jaw. 



(b) N'esfs under stones. — As is well known, wherever there are sto.ies 

 on dry declivities, etc., innumerable ants' nests are found under tfiem. 

 The stone serves as a roof, under which are the most beautiful corridors 

 and chambers. Under these lies the mined nest. The stone serves, 

 above all, to produce a speedy warming by means of tlie rays of the 

 sun. The ants under it are always in the highest story, in damp or cool 

 weather, as soon as the sun shines or begins to iienetrate. As soon as 

 the sun disappears the insects go below. They also go below when the 

 sun shines too strong. 



The same species which mine, and which build earthen structures 

 above ground, also live under stones as soon as they find any. The stone 

 must be neither too small and thin nor too thick and large. Stones of 

 2 to 15 centimeters in thickness are the most desirable, according to the 

 size of the ants and the extent of their colonies. They allow the best 

 regulation of the heat for the brood. 



The si)ecies of Lasius, Formica, Myrmica, Tetramoriuin, Plar/iolepis, 

 Pheidole, Camponotus, Aphw7io(jastcr, Bothriomyrmex, Tapinoma, and 

 other genera, are found in swarms under stones among us in Europe. 

 There are few genera of ants that never live under stones. 



(c) Earth structures above ground. — Many kinds of ants are excellent 

 masons, but by no means all. It is easier to mine than to construct 

 walls, vaults, and pillars. 



1 advise everyone who wishes to see one of the most beautiful dis- 

 plays of animal instinct and animal intelligence to equip himself with 

 an umbrella, and with patience, on some warm day in May, when it 

 begins to rain after a drought, or when it has just stopped raining, to 

 repair to -a meadow, and there, with the greatest perseverance, to 

 watch attentively the surface of the ant-hills and the actions of their 

 occupants. He must at the same time watch closely individual ants 

 and their work. He will then admire the skill and foresight of these 

 insects, and will see how the little architects and masons understand 

 how to turn every blade of grass, every stalk, every leaf, to account, by 

 means of their earth mortar, in the erection of vaults, pillars, walls, etc. 

 In this manner are made those no less numerous than wonderful earth 

 labyrinths which serve the ants in our meadows as conical super- 

 structures. Our tig. 9 represents a fragment of the moun<l of an earth 

 nest of Lasius niger. It can be seen how blades of grass and leaves are 

 used in the masonry as pillars, arches, etc. The drawing, which is two- 

 thirds of the natural size, was made by Mr. L. Schroter, like all the others, 

 from the original piece, which I had hardened with a solution of silica. 

 I need not add that a mined nest always lies under the superstructure 



