136 DESTEUCTION OF INSECTS. 



their small dimensions enable tliem to retire, are all circumstances 

 very favorable not only to tbe perpetuity of their species, but to 

 their transportation to distant climates and their multiplication in 

 their new homes. The teredo, so destructive to shipping, has 

 been carried by the vessels whose wooden walls it mines to almost 

 every part of the globe. The termite, or white ant, is said to 

 have been brought to Rochefort by the commerce of that port a 

 hundred years ago.* This creature is more injurious to wooden 

 structures and implements than any other known insect. It eats 

 out almost the entire substance of the wood, leaving only thin 

 partitions between the galleries it excavates in it ; but as it never 

 gnaws through the surface to the air, a stick of timber may be 

 almost wholly consumed without showing any external sign of 

 the damage it has sustained. The termite is found also in other 

 parts of France, and particularly at Eochelle, where, thus far, its 

 ravages are confined to a single quarter of the city. A borer of 

 similar habits is not uncommon in Italy, and you may see in that 

 country handsome chairs and other furniture which have been 

 reduced by this insect to a framework of powder of post, covered 

 and apparently held together by nothing but the varnish. 



Dest/ruction of Insects. 



It is weU known to naturahsts, but less f amiharly to common 

 observers, that the aquatic larvae of some insects which in other 

 stages of their existence inhabit the land, constitute, at certain 

 seasons, a large part of the food of fresh-water fish, while other 

 larvae, in their turn, prey upon the spawn and even the young of 

 their persecutors.f The larvae of the mosquito and the gnat are 



length. Between the hole, and the outside of the leaf of the table, there were 

 forty grains of the wood." It was supposed that the sawyer and the cabinet- 

 maker must have removed at least thirteen grains more, and the table had been 

 in the possession of its proprietor for twenty years. 



* It does not appear to be quite settled whether the termites of France are 

 indigenous or imported. See Quatrefages, Souvenirs d'un Naturaliste, ii., 

 pp. 400, 542, 543. 



The white ant has lately appeared at St. Helena and is in a high degree de- 

 structive, no wood but teak, and even that not always resisting it. — Nature 

 for March 2d, 1871, p. 362. 



f I have seen the larva of the dragon-fly in an aquarium bite off the head of 

 a young fish as long as itself. 



