BOOK XVI. lAxix. 219-LXXX. 221 



sea-going vessels, and the same witli all vvoods 

 except thc wild and the cultivated oHve ; in fact 

 some woods are more Hable to faults in the sea and 

 others in the ground. 



LXXX. There are four kinds of pests that attack Creatures 

 timbers. Borer-worms " have a very large head in pro- JS^^"* '^ 

 portion to their size, and gnaw away wood with their 

 teeth ; these worms are observed only in the sea, 

 and it is held that they are the only ones to which 

 the name of borer-worm properly appHes. The land 

 variety are caHed moths, but the name for those 

 resembHng gnats is thrips, and there is also a fourth 

 kind belonging to the maggot class, of which some 

 are engendered by the wood itself when its sap 

 becomes putrid and others are produced by the 

 worm caUed horned-worm — as they are in trees — 

 which when it has gnawed away enough to be able 

 to turn round, gives birth to another. The birth 

 of these insects is prevented however in some trees, 

 for instance the cypress, by the bitter taste of the 

 wood, and in others, for instance the box, by its 

 hardness. It is also said that the fir wiH not decay 

 in water if about the time of budding and at the 

 lunar period we stated it is stripped of its bark. The § 190, 

 companions of Alexander the Great stated that on 

 the island of Tylos^ in the Red Sea there are trees^ 

 nsed for building ships, the timbers of which have 

 been found continuing free from rot for two hundred 

 years even though they were under water. They 

 further reported that the same island contains a 

 shrub growing only tliick enough for a walking 

 stick, marked with stripes Hke a tiger skin, heavy 

 and Hable to break Hke glass when it faUs on to 

 things of harder substance. 



