508 EUCALYPTS OF THE COUNTY OF CmiBERLAKD, 



very different opinions wliicli men of science have expressed on 

 the subject. The Eev. J. E. Tenison-Woods, F.G.S.,, andF.L.S., 

 in a paper eatitled " Tasmanian Forests: their Botany and Economic 

 Value, ^"^ asserts, on the testimony of a gentleman who has had 

 great experience in such matters, that the tallest trees of the 

 forest, the giant timber of Tasmania, range from fifty-one to 

 seventy-five years old. Sir William Denison, on the other hand, 

 arrived at the conclusion, from observations which he made near 

 Hobartown, that ^. ^/oJ«^/w5 continues ''its upward growth in 

 deep nutritive soil for about 80 years, after which space of time, 

 the tree will onty enlarge in the girth of its stem and branches." 

 Baron Mueller regards this gum tree as a species of longevity, 

 but he thinks that Professor Langethral has erred greatly in 

 allowing it an age of 2300 years ! The fact is, as pointed out by 

 the Eev. J. E. Tenison-Woods, and also by the learned Baron, 

 little reliance can be placed on any estimate based on the rings 

 of wood added to the diameter each year, because ''the less 

 reo-ular intermediate rings between the annual layers of wood, 

 apt to be formed in trees of the zone of evergreen vegetation, are 

 easily mistaken for the results of a year's growth." Whatever 

 may be the ages of the Tasmanian Eucaljrpts, I believe that the 

 harder woods in the county of Cumberland are slow in growth, 

 and that centuries elapse before they reach their full proportions. 

 Some years since when I was residing in Parramatta, I came to 

 the conclusion (from observing trees which had sprung up since 

 the formation of the settlement, and also from measuring two 

 trees that had been planted by the late Miss Elizabeth Macarthur 

 half a century previously) that the growth of some species is by 

 no means rapid, and that the Ironbark (E. sideroxylon) had not 

 made more than a foot in diameter in fifty years. The Blackbutt 

 (E. inhdaris) and the Cumberland Blue Grum (E. salignaj are 

 generally regarded as trees of rapid growth, but I believe, as I 

 remarked in my " Gniirilution to the Flora of Australia,'''' p. 223, 

 that " differences of soil, the prevalence of drought, the ravages 



