White Ants. 329 



insects which feed on wood to prefer what is unsound ; the 

 same principle holds with respect to fungi, lichens, and other 

 parasitical plants. 



All the species of Termites are not social ; but the solitary 

 ones do not, like their congeners, distinguish themselves in 

 architecture. In other respects, their habits are more simi- 

 lar; for they destroy almost every substance, animal and 

 vegetable. The most common of the solitary species must 

 be familiar to all our readers by the name of wood-louse 

 (Termes pulsatorium, LINN. ; Atropos lignarius, LEACH) one 

 of the insects which produces the ticking superstitiously 

 termed the death-watch. It is not so large as the common wood- 

 louse, but whiter and more slender, having a red mouth and 

 yellow eyes. It lives in old books, the paper on walls, col- 

 lections of insects and dried plants, and is extremely agile in 

 its movements, darting, by jerks, into dark corners for the 

 purpose of concealment. It does not like to run straight 

 forward without resting every half-second, as if to listen or 

 look about for its pursuer, and at such resting times it is 

 easily taken. The ticking noise is made by the insect beating 

 against the wood with its head, and it is supposed by some 

 to be peculiar to the female, and to be connected with the 

 laying of her eggs. M. Latreille, however, thinks that the 

 wood-louse is only the grub of the Psocus abdominalis, in 

 which case it could not lay eggs ; but this opinion is some- 

 what questionable. Another death-watch is a small beetle 

 (Anobium tesselatum). 



