THE SILVER F1K. 401 



instinct to rest where its enemies may be unable to distin- 

 guish its yellow wings from the surrounding foliage. If 

 driven from one of these places of retreat, it flies a short 

 distance and alights on another. 



The Silver Fir was called by the Eomans Abies, a name 

 which, by an error of the early botanists, was given to the 

 Spruce Fir ; and hence considerable confusion has arisen. 

 It was much used by the ancients in ship-building, and 

 was considered by Virgil the fairest ornament of the 

 mountains. It is a native of the mountainous parts of 

 central Europe, and of the west and north of Asia, but does 

 not extend so far north as the Spruce or Scotch Fir, nor, 

 from its preferring a milder climate, is it found at so great an 

 elevation as these trees. In dimensions it is one of the most 

 striking of the tribe, rising frequently to the height of a hun- 

 dred and sixty or even a hundred and eighty feet, with a 

 stem perfectly erect and generally clothed from the base to 

 the summit with regular tiers of horizontal branches, and 

 often measuring as much as six or eight feet in diameter. 

 For many years the bark is smooth and of a greenish grey 

 colour ; but as the tree gains age, it becomes rough with 

 small fissures ; and when very old, it often throws off the 

 outer part in large flakes, leaving the recent bark of a deep 

 rich brown. Pliny relates that an enormous ship, which 

 was built to transport an obelisk from Egypt to Eome, had 

 for its mast a Silver Fir measuring twenty-four feet in 

 circumference. 



It is supposed to have been introduced into England 

 about the beginning of the seventeenth century, and is 

 now very common. Specimens are in existence which 

 have attained the height of a hundred and fifty feet, 

 with a trunk sixteen feet in diameter. "The timber 

 of British growth is found to be of excellent quality, 

 and adapted for almost all purposes to which the wood 

 of the Pine is applicable ; it possesses both elasticity and 

 strength; its grain being straight and even, it is not 

 subject to warp or twist, even when sawn out of the green 



