rUEBIDENX's ADDRESS. 167 



observer can consult his own leisure for studying their natural 

 habits; for detecting their modes of reproduction, and those 

 which may undergo any metamorphosis; and for undertaking, 

 or repeating, his microscopic examinations of them. 



Man, with his confined and imperfect power of vision, must, 

 for these minute beings, call in aid that wonderful and improved 

 instrument, the microscope. Neither do I despair of all further 

 improvement in that beautiful instrument; but I trust, indeed, 

 that it may be still brought to a higher degree of perfection, 

 both in its magnifying power and in its presenting a greater 

 compass of light. And I look forward with great hope that 

 means of transferring the magnified object, by the aid of photo- 

 graphy, to jDaper, will be rendered more easy and more certain; 

 and thus permanent light-pictures, representing many of the 

 secrets of nature in her lower form, w^ll be afforded to the 

 Naturalist. 



In having just spoken of the Royal Oak, or Quercus 7vbur, as 

 the " Sovereign" of our northern forest-trees, and with reference 

 to the interesting " Abstract" of Mr. D. Oliver's paper " On the 

 Growth in Diameter of the Dicotyledonous {Exogenous) Stems," 

 published in p. 64, of our Transactions, vol. 3, pt. 2; and in 

 relation to the breadth of, and variation in, the annual concen- 

 tric zones, I beg to call your attention to a recently discovered 

 forest-tree, which growls in the uncultivated waste of California, 

 in North America, at an altitude of from 4,000 to 5,000 feet 

 above the Pacific. This stupendous and gigantic tree, although 

 an evergreen (^Conifer), evidently deposes our northern Oak from 

 his sovereignty of the vegetable kingdom, and stands almost un- 

 rivalled in majesty, dimensions, and height, among the trees of 

 the forest.* This " Mammoth Tree," or WelUngtonia gigantea^ is 

 from 300 to 400 feet in its entire height, the diameter being 

 more than 30 feet, and the circumference above 90 feet, at its 



* The Rev. T. Ewing describes a place, which he called the " Vale of Giants," in Tas- 

 mania, where he discovered, in 1849, some enormous Eucalypli, or Swamp Gum Trees. 

 The largest he measured, was, at a j'ard from the ground, 102 feet, and at the ground, 

 130 feet in circumference. Another he reckoned at more than 300 feet in height. (.S>e 

 p. 155, vol. 1, "Trans, of the Royal Society of Van Dieman's Land.") I believe, how- 

 ever, that the Eucalyptus is a tree of very rapid increase. 



