1880.] NATURAL SCIENCES OF PHILADELPHIA. 343 



was further interesting to note tliat in most cases the crops of 

 young plants in each area were about the same age in each case, 

 as if the seeds in the several locations had all started to grow 

 together in some one particular year, and probably at no other time. 

 On the naked ^^laces, where few or no trees were now found, the sur- 

 face would be closely covered bj^ a matted growth of a grass almost 

 peculiar to that I'egion, Danthonia compressa, but a close examina- 

 tion of the surface showed occasional tracts of deep vegetable 

 mould which had been formed by ages of deca^ying Hypnum or 

 Sphagnum moss, and the evident remains of roots, just as we now 

 find under the Balsam trees, and there is no doubt from these 

 facts that these steep upper declivities were once clothed with 

 trees and mosses, to which the grass previously named succeeded. 



With these facts in mind he examined the arboreal features of 

 the White Mountains in New Hampshire. On Mount Washington, 

 which is a little over 6000 feet, the timber runs up to about 4000 

 feet ; while Mount Webster, a mountain forming the southern 

 peak of the same chain, and about 4000 feet high, has little timber 

 above 3000 feet. Clearly, climatic reasons will not account for 

 these peculiarities. On Mount Washington there is much of the 

 same character as distinguishes the foi'ests of the Rocky Moun- 

 tains. As already noted the timber line becomes marked at about 

 4000 feet. For at least another thousand feet we meet witli 

 sci'ubby bushes of Abies Balsamea, Abies yiigra^ and Abies alba, 

 with some Betula papyracea. Beyond this, and almost to the 

 summit, an occasional specimen of one or another of the conifers 

 may be seen. As noted in regard to the Colorado scrubbj^ growth, 

 none of these had ever produced seed ; nor was it at all probable, 

 from a careful survey of the locations, that many of the areas 

 could have been seeded by the winds, however strong, bringing 

 the seeds up these mountain heights. Moreover, there were many 

 cases where there were intermediate areas clear of all scrubby 

 spruce plants, and where seeds could be brought by winds in 

 these modern times much easier than to the heights above. 

 Besides this, it was evident that many of these dwarfed specimens 

 were of immense age. Some that he examined were certainly 

 fifty 3'ears old, though the stems at the ground were no thicker 

 than his wrist, and, trailing on the ground, occupied but 

 16 or 20 square feet of space. There seemed to be but little 

 doubt that at some time in the past Mount Washington had 

 forests of conifeme at much higher elevations than at present, if 

 not perhaps clean up to the summit ; that these scrubby plants 

 now there were seedlings that had sprung up under the elder 

 ones, and that in time the older ones were destroyed, leaving the 

 small ones beneath alone to their fate. 



An examination of different parts of Mount Washington shows 

 not only that this is the true explanation of the absence of good 

 timber beyond what is known as the timber line, but that the 

 same law is in progress to day as in centuries past. Illustrations 



