At the meeting of the Botanical Section of the Academy of Natural Sciences, of Philadelphia, Mr. Thomas Meehan remarked that there was nothing phenomenal in the great age of the mammoth Sequoias, as other trees on the Pacific Coast exhibited great age. In order to ascertain whether more than one annual circle of wood is formed in each year, he tested the matter in various ways. For instance, a pine or spruce would be found to make an average growth of a foot a year up to fifteen years old; from that to about thirty years, nine inches; from that on, six inches; after that a stage was reached where the erect growth ceased to any considerable extent, and the growth force seemed turned towards the lateral branches. In the pine forests of the Pacific Coast there was no danger of error in fixing the age of the average tree of sixty feet high at about fifty years. Whenever such a tree was cut down, and an opportunity afforded to count the circles, they would be found to correspond so nearly with the calculated age, as to prove that it was quite safe to assume a single circle for a single year.

Then there was a remarkable degree of uniformity in the diameter of these annual growths in most trees, so that when once we had the number of circular lines to an inch, and the diameter of the tree, we could tell its age near enough for general purposes. In some pine trees growing on very rich soil, he had found as few as about four circles to an inch. For instance, a section of a Pinus Lambertiana in Mariposa, four feet across, had but 189 circles; but here the increased size of the trees corresponds with the larger annual circles. Trees of this species of pine here measuring thirty, and a few thirty-three feet round were not uncommon. No matter, however, how vigorous may be the growth of trees under fifty or over one hundred years, they decrease with age, and we may safely allow six rings to an inch in these older sugar pines, which would make the thirty-three feet tree 396 years old. The outer growths of sequoia were very narrow. He counted as many as eighteen to the inch, while the rings in the interior of cross-sections would show about six to the inch.

Allowing twelve as the average per annum, a tree of thirty-three feet diameter would give 2,376 years old, which is about the same as given by an actual count of the rings.

At Harrisburg, or Juneau, in latitude 580, a Sitka spruce (Abies Sitkensis) cut down gave 149 rings from center to circumference - 298 lines in a trunk three feet across. This gave an average of about eight to an inch in this 149-year-old, three-foot tree. At Wrangel, latitude 560 30', a tree of the Western Hemlock (Abies Mertensiana) which had been blown down and afterwards divided by a cross-cut saw at four feet from its base, gave eighteen lines to an inch, and the annual growths seemed very regular almost to the centre of the tree. It was six feet in diameter, and must have been a grand old tree in its day. It had evidently been broken off years before it was blown down, but the length of the trunk up to where it had been broken was 132 feet, and four feet in diameter at that height. But allowing as much as twelve to an inch, it would give for the point cut across, six feet, an age of 432 years. At Kaigan Harbor, latitude 550, the Sitka spruces were very large, and of great height. He measured two of the largest, which were twenty-one feet in circumference each. Allowing eight to the inch, as in the tree of the same species at Harrisburg, it gives 336 years as the age of the tree.

So far as appearances went, these trees were in the height of vigor, and there seemed no reason, judging from experience in other cases, why these trees might not flourish for a hundred years yet. Mr. Meehan had no doubt that these trees in these latitudes in Alaska would easily have a life of 500 years.

Turning now to the Atlantic States, we find 200 years as the full average term of life for its forest trees, with the exception, perhaps, of the plane (Platanus occidentalis), which is the longest lived of all. Trees famous for longevity in Europe are comparatively short lived here. In the old Bartram Garden near Philadelphia, and where the trees can be little more than 150 years old, nearly all are past their best. The English oak (Quercus Robur), which in England is said to live for a thousand years, has grown to full size and wholly died away in this garden, and the foreign spruces are on the down grade. The great cypress (Taxo-dium distichum), and which must have made an average growth of four lines a year, has also begun to show signs of deterioration. Silver firs (Abies pectinata) in the vicinity of Philadelphia known to be planted in 1800 are decaying. This is the general experience.

In seeking for the cause of this difference we are accustomed to look at the relative humidity of the atmospheres of Great Britain and the Atlantic United States. Evergreens like Cerasus Lauro-Cerasus, Laurus nobilis and Viburnum tinus, which will endure a temperature of 250 below freezing point in Great Britain, are killed by 10° in Philadelphia; and, it is believed, by the dryer atmosphere causing a heavier drain for moisture on the vital powers of the plant to supply. A strain which will wholly destroy plants in some instances, must have an enervating influence where it does not wholly destroy, and this would naturally be exhibited in shortening the life of the tree.

The climate of Alaska had the same favoring influences we found in Great Britain. The warm Sea of Japan flowed against its south-eastern face, along which the trees referred to were found. The atmosphere was always moist, and severe weather almost unknown. At Sitka, in latitude 570, as much as 100 inches of rain had fallen in a single year. The harbor was rarely frozen - boats came in and went out at all times of the year. There were some winters when no ice of any consequence was seen. These were circumstances favorable to longevity in trees.

Mr. Meehan concluded by remarking that Dr. Lindley had said somewhere that his researches had failed to show that there was any period of duration of life set for any tree, and that if circumstances favored there seemed no reason why trees might not live for an indefinite period, and therefore arguments offered in connection with the " wearing out of varieties " based on what is called the " natural life of a tree " had little force. Mr. Meehan believed his observations on the longevity of trees on the Pacific Coast confirmed Dr. Lindley's views. At any rate, there seemed nothing phenomenal in the age of the Sequoia gigan-tea, as other species partook of similar longevity to a great extent.