(4 ) 



work, they form innumerable galleries, 

 all of which lead to a central point, and 

 in their work they seem carefully to 

 avoid piercing the surface of the wood. 

 Hence the articles which thej have per- 

 forated appear perfectly sound, when 

 the slightest touch is almost sufficient 

 to cause them to fall to pieces. "* 



In connection with the depredations 

 of the various forms of Xylophaga, it 

 will be well to call attention to certain 

 species of wood referred to in the paper 

 on "Australian Forest Trees," read by 

 me at a meeting of the Academy on 

 the first of last July.f In said paper, 

 I mentioned the Eucalyptus marginafa 

 (Smith), of which Dr. Mueller says: 

 "The Jarrah or mahogany -tree of S. 

 W. Australia, famed for its indestructi- 

 ble wood, which is attacked neither by 

 Chelura, nor Teredo, nor Termites, and 

 therefore so much sought for jetties and 

 other structures exposed to sea -water, 

 also for underground work, and largely 

 exported for railway sleepers. Vessels 

 built of this timber have been enabled 

 to do without copper- sheathing. It is 

 very strong, of a close grain, and a 

 slightly oily and resinous nature ; it 



* Baird's Diet. Nat. Hist., p. 542. 



t "On the Economic Vahie of certain Aus- 

 tralian Forest Trees, and their cultivation in 

 California." This valuable paper was printed 

 in full in Vol. II of the California Hoeticult- 

 UEisT, pages 271, 313, 326, 355.— Er>. 



works well, takes a fine finish, and is 

 by ship -builders here considered supe- 

 rior to either Oak, Teak, or indeed any 

 other wood." * * * The K rostrafa 

 (Schlecht) — the Red Gum of Victoria — 

 is another very valuable species for the 

 " extraordinary endurance of the wood 

 underground, and for this reason highly 

 valued for fence -posts, piles, and rail- 

 way sleepers; for the latter it will last a 

 dozen years, and if well selected much 

 longer. It is also extensively used by 

 ship -builders. * * * Next to the 

 Jarrah from S. W. Australia, this is the 

 best wood for resisting the attacks of 

 sea-worms and white ants. This species 

 reaches a hundred feet in height. 



A consideration of the above facts 

 indicates the course to be pursued. The 

 cultivation of the species of Eucalyptus 

 named herein, would, if commenced^ 

 immediately, supply us in ten or twelve 

 years with an indestructible timber for 

 submarine wood -work, and prove a 

 profitable enterprise for the capital in- 

 vested, as well as a great public benefit. 

 But even if a much longer time were 

 required to produce trees of either of 

 these species (whose qualities are so 

 particularly specified by Dr. Mueller) 

 of dimensions suitable for submarine 

 structures, nevertheless the importance 

 of their cultivation is so palj^able as to 

 make further comment unnecessary. 





