ANTS AND ANT LIFE. 81 



trunks. They take care, above all things, that the wood 

 fibres shall remain in their natural position, but Otherwise 

 work in the most diverse fashions according to circum- 

 stances. Walls and pillars and buttresses run always 

 parallel with the wood fibres, while a covering wall is al- 

 ways left outside of at least a centimetre in thickness, which 

 is only pierced by a few entrances and outlets. If a 

 larger hole chances to be made in this outer covering the 

 inhabitants retire inwards, and try to stop up the opened 

 galleries and rooms with sawdust and other materials. 

 They also very often use in their building the spaces al- 

 ready made by other ants and insects, especially by the 

 larva? of the woodlouse. 



" Imagine," says Huber, " the inside of a tree completely 

 gnawed out, with countless more or less horizontal stories, 

 five or six lines apart from each other, card-thick roofs 

 earned now on perpendicular partition-walls, now on a 

 number of little pillars, and in this way countless single 

 rooms or cells all in black-colored and smoked looking 

 wood, and then you will have a picture of these ant- 

 towns." 



The Rev. H. C. McCook has published some very in- 

 teresting observations on a kind of wood- working ants in 

 America (Camponotus or Formica Pennsylvanicus, the 

 Pennsylvanian Carpenter, " Transactions of the American 

 Entomol. Soc., December, 1876). He describes a regular 

 system of galleries, passages, rooms, halls, and vaults, which 

 this ant made in a corner beam in an ironworks, in Blair 

 Co., Pa., and says that such nests in trees had been found 

 to attain the length of six feet. Forel has observed the 

 greatest diversities of building among the F. trundcola. It 

 can build walls like the blood-red ants, and use long beams 

 like the turf -ants. It can erect domes and secondary domes, 

 but can also build a nest under a stone. It can even 

 establish itself in old tree trunks, and utilise the concentric 

 layers of wood to make spacious rooms. The wood-building 

 ants also know how to utilise their materials in the most 

 diverse ways, and every material is good enough for them 

 if it serves their purpose. If beams fail they use round 

 poles, but these leave holes in the building and are less firm 

 The journals of the Scientific Society of Bern, for the year 

 1874 (p. 41), contain the account of an incident in which 



