312 ANNUAL OF SCIENTIFIC DISCOVERY. 



more than one row of them occur in the direction of the length of the fiber, 

 and what is very unusual, present radiating lines from the central depression 

 to the circumference. Second, the inner zone of each annual ring of wood is 

 narrower, of a dark color, and formed of more slender woody fibers, with 

 thicker walls in proportion to their diameter. These tubes have few or no 

 discs upon them, but are covered with spiral striag, giving the appearance of 

 each tube being formed of a twisted band. The above characters prevail in 

 all parts of the wood, but are slightly modified in different rings ; thus the 

 outer zone is broader in some than in others, the disc-bearing fibers of the 

 outer zone are sometimes faintly marked with spiral stria?, and the spirally 

 marked fibers of the inner zone sometimes bear discs. These appearances 

 suggest the annual recurrence of some special cause that shall thus modify 

 the first and last formed fibers of each year's deposit, so that that first formed 

 may differ in amount as well as in kind from that last formed, and the peculiar 

 conditions of an Arctic climate appear to afford an adequate solution. The 

 inner or first formed zone must be regarded as imperfectly developed, being 

 deposited at a season when the functions of the plant are very intermittently 

 exercised, and when a few short hours of hot sunshine are daily succeeded by 

 many of extreme cold. As the season advances the sun's heat and light are 

 continuous during the greater part of the twenty-four hours, and the newly- 

 formed wood fibers are hence more perfectly developed ; they are much larger, 

 present no signs of stria?, but are studded with discs of a more highly organ- 

 ized structure than are usual in the natural order to which this tree belongs." 



At a recent meeting of the Geological Society, London. Sir R. J. Murchison 

 stated that from an examination of the geological specimens brought home by 

 the recent various English Arctic expeditions, he inferred that the oldest sedi- 

 mentary rock of the Arctic archipelago is the Upper Silurian limestone, which 

 contains several corals and other fossils known in the formations of that age 

 in Gothland, "Wenlock, and Dudley. No clear evidence has been afforded as 

 to the existence of Devonian rocks, though extensive masses of red and brown 

 sandstone may belong to that formation. True carboniferous Producti and 

 Spiriferi have been brought home by Sir E. Belcher from Albert Land, north 

 of Wellington Straits ; and coaly matter has been detected in many localities. 

 Secondary rocks, it is surmised, may exist in the smaller islands north of 

 Wellington Channel, as fossil bones of saurians were found in them. As there 

 are no clear traces of the older tertiary rocks, the author inferred that the 

 older deposits of the Arctic region had been elevated at an early period, and 

 had remained in that position during a very long time ; for the objects to 

 which the attention of the geologist is next drawn by the collections of the 

 voyagers, are certain silicified stems of plants, which are widely spread over 

 all the islands, between Wellington Channel and the east and west coasts of 

 Banks's Land, and which, from the examination already bestowed on them 

 by Dr. Hooker, appear to bo allied to, if not identical with, coniferous trees. 

 At one spot, namely, Coxcomb Range, Banks's Land, and at a height of 500 

 feet above the sea, Captain M'Clure collected a large Cyprina, undistinguish- 

 ablo from C. islandica of the glacial drift of the British isles. There are small 



