EXOGENOUS SERIES NEEDLE LEAF WOODS. 187 



Big or Mammoth trees have been measured up to three hundred and 

 twenty feet in height and thirty-five feet in diameter (Sargent). They are 

 thus the largest of American trees and the most massive, although not the 

 tallest, of all trees Specimens twenty-five feet in diameter have been 

 estimated as thirty-six hundred years old, and it is thought that under 

 favorable conditions trees can survive for five thousand years, or even 

 longer. The oldest trees are sound throughout. The almost incombustible 

 bark is nearly two feet in thickness; the wood is brittle, but otherwise 

 resembles ordinary redwood. It should be noted that large exceptional 

 trees are all known, and that most of them have names such as the " Pride 

 of the Forest," the "Grizzly Giant," and the "U. S, Grant." These, with 

 younger trees, are grouped in the Mariposa, Calavaras, and other groves. 

 Many sawmills are unfortunately engaged on the trees of this species, the 

 notably large specimens of which do not exceed several hundred. 



The history of a Redwood tree, dating from two hundred and seventy- 

 one years before the Christian era, was reported by Prof. Dudley to the 

 United States Senate, through the late Honorable O. H. Platt of Con- 

 necticut, on February n, 1904. The record, obtained by counting the 

 concentric layers of growth on the cross-section of the felled tree, showed 

 that forest fires had occurred during the years 245, 1441, 1580, and 1797 

 A.D. The last fire was locally severe, since it charred a space thirty feet 

 high and eighteen feet broad. Recovery from such wound is evidence as 

 to the vitality of the species, and it is interesting to note that the new 

 tissue was full, even, and continuous, as deposited above the wound. 



The vitality of the redwood is remarkable. Its ability to reproduce by 

 sprouts from the parent stump is almost phenomenal. The redwood tree 

 resists forest fires as well as any other known species,* and repairs wounds 

 that would destroy many other trees. The thick roots project downward 

 so sharply as to suggest inverted funnels, and are so vigorous that trees are 

 seldom uprooted by the winds. Growth is rapid, trees having been 

 known to develop heights of eighty feet and diameters cf sixteen inches 

 within thirty years. The genus is thus unusually important, first, because 

 of the present value of the wood, and, second, because the quick-growing 

 healthy trees are likely to resist commercial extinction. 



Redwood trees may be known by their size, locality, and 

 fine, dull, evergreen foliage. The name Sequoia is that of an 

 Indian chief. The two species must be distinguished. Common 

 redwoods are nearer the coast; they "follow the fogs." Some 

 of the trees are so great as to be confused with other " giant " 

 redwoods (S. Washingtonia}. 



* This is because the thick bark resists fire, and also, to some extent, because 

 trees (Sequoia sempervirens) thrive in moist places 



Reference: "The Big Trees of California," U. S. Forestry Division, Bulletin 

 No. 28. Also Mr. Jas. Horsburgh, Jr., Southern Pacific Railway. 



