Can Plants Sleep for Centuries? - A Canadian botanist writes : ". I read the very interesting account of your Alaska trip. There are some facts in it of which I shall take advantage as occasion presents. I observe that you include in your list Aconitum Napellus. I should much like to know whether the plant you found is the one usually cultivated in English gardens, (in which case it will not be native on the Pacific coast,) or is it a form of the indigenous and polymorphous A. delphinifolium? The latter has been regarded as a variety of Napellus by several botanists, but it appears to me to be quite distinct, the racemes much shorter and more or less corymbose, with longer pedicels; the flowers brighter and of more delicate texture; foliage less coriaceous, paler, and of a brighter green, etc. Your remarks on the suspension of growth in plants, under the influence of cold, for protracted periods, are of special interest, and, I may add, importance. The subject attracted my attention some years ago, during a brief visit to the Rocky Mountains of the South, and from an entirely different point of view from that suggested to you.

I have now an experiment in progress, started eighteen months ago, to ascertain whether roots adapted for cattle feeding, cannot be kept for an indefinite period in a fresh succulent condition.. In a cellar on my farm here, the cellar built on a Colorado model, I have Mangel Wurzel roots as solid and succulent now as when they were taken out of the field in October 1883. They were kept all last summer without ice or artificial cooling, except that afforded by the cellar, and did not show any but the very feeblest attempt to sprout, and that very late in autumn, and only in some of the roots. The result of the experiment so far is of great practical importance, but I am desirous of ascertaining how far it can be carried. Our farmers here have hitherto had the greatest difficulty in keeping their Mangels good over the first winter, or until the advent of green grass in spring. I hope to be able to show them that they can provide summer as well as winter feed by growing roots, and thus be independent, to a large extent, of bad or late, or drouthy seasons".

[The above refers to a paper on the Flora of Alaska, contributed to the "Proceedings of the Academy of Natural Sciences, of Philadelphia," by the Editor of this magazine. As the subject has a practical value outside of its abstract scientific relation, we give below an extract referring to the above suggestions of our correspondent. - Ed. G. M].

'On our return from Chilcat (written Tchillcat in some charts) down the Lynn Channel, we ran up Icy Straits into Glacier Bay, to the fifth or Muir Great Glacier; and on our return, passed in between the Beardslee Islands to the mainland at a point opposite Cross or Icy Sound in about lat. 58.30, called on our chart Bartlett Bay. This is on a peninsula formed by the junction of Icy Sound with the Lynn Channel, and nothing seems to be known of this immense tract of land, except what can be gathered from the not over-friendly Indians who live along the coast in the fishing season. An Indian trader, Mr. Richard Willough-by, told the author that at a point about twenty-five miles above this he had traveled northwest across the peninsula for some forty miles to Pyramid Harbor, near the mouth of the Chilcat, as he was understood to say wholly on ice. It is quite probable that at about a hundred miles north from Bartlett Bay the country is a vast ice-sheet, and there were circumstances which seemed clearly to show that at no great distance of time in the past the whole of the western portion of this peninsula was covered by ice; while on the eastern shore, on Lynn Channel, the forest trees showed the mixture of trees of various ages common to old forests, the forests of the western slope were all comparatively young, and none were evidently over fifty years of age.

The earth to fifty feet or more in depth in many places was composed wholly of glacial drift, and on this were the young forest trees. Some remarks on these features more in detail are given at page 187, 1883, of the " Proceedings of the Academy." Since they were published, Mr. Dall has kindly informed the author that there is historical evidence to show that this part was covered by ice at about the end of the past century. This being so, it becomes a matter of considerable interest to ascertain how so many plants have maintained an existence here - whether they have appeared since the recession of the ice, or whether they managed to retain their hold during the whole continuance of the ice-sheet.

At our landing place a small stream entered the ocean, and this stream came through a swampy valley a few hundred feet wide, extending into the land for an unknown distance. The hills of drift were on each side of this valley. All the plants were collected within a quarter of a mile of the mouth of this stream, and there is every reason to believe that a larger number of species might have been collected had there been time or opportunity for more inland research along its line. By the margin of the swamp were rocks from five to ten or twenty feet above its ground level, and not covered by drift; but on the more level rocks often with a few feet of sand, which had evidently blown in during the course of years. Yet with every opportunity to do so had there been time for the work, very few of the plants along the line of the stream had extended to the drift deposits close by. These plants were not brought there by the drift. We may say almost with certainty that they were there during the period when the land was covered by ice.

How did they manage to maintain themselves under these circumstances? Were they wholly covered by the ice; or were there rifts and clefts in the ice-sheets deep enough to allow plants a summer of recuperation ?

I think we need not regard the last consideration as one of necessity. There is reason to believe that under a low temperature plants will retain vital power for an indefinite period. Mr. Douglas, of Waukegan, Illinois, once sent to me young trees of Catalpa speciosa, that had been placed in sand in a cool cellar and forgotten a year, and that remained the whole twelve months dormant, and grew the next year when planted out. Dr. Maxwell T. Masters, of London, has called attention to the case of an orchid which, as I remember, remained under ground a whole season without growing, and this has been adduced as a probable explanation of the non-appearance in some seasons of plants which are plentiful in others. If a plant will remain dormant one, two or three years under unfavorable conditions for growth, who shall say how much longer a period they may not live, under conditions favorable to dormancy only ? I have a strong suspicion that just at or below the freezing-point, roots may live for an unlimited number of years; and that a district might be covered by an ice-sheet for a quarter of a century or more, and the plants beneath retain full vital powers.

By referring again to my remarks on some geological features of this part of Alaska (page 183, Proc. Ac, as cited), it will be seen by a sunken forest of apparently modern trees there is reason to believe that in comparatively recent times this peninsula was clothed with a rich vegetation - that it was of a sudden partially submerged and perhaps as suddenly elevated again a little - and that all these changes have been the work of but a few hundred years. The plants in question have probably survived through all these changes, though perhaps wholly ice-covered at times, and have not been brought here by modern agencies; and if these suggestions, which are offered only as great probabilities, should get fuller confirmation from any one in the future who may have opportunities of going more fully into an investigation of the spot, it will give additional interest to the study of botany in connection with the great changes which have been going on over the surface of our globe.

From other botanical evidences which southeastern Alaska affords, I am inclined to believe that geological changes in this section have not required the long periods to effect which geologists usually demand. In the vicinity of the Davidson Glacier, a little below Pyramid Harbor, layers of ice may be seen covered by sand and earth, and prevented from rapid thawing - only an occasional spot showing the icy bed beneath - and yet alder and other plants grow within a few hundred yards. On the other hand, near the Muir Glacier, at the point where the river-bed beneath the ice diverges from the glacier's direct course, the only sign of arborescent vegetation is from a few score of willow-bushes, scattered on the mountain-side. Beneath the drift, hundreds of feet below, is a forest buried as it grew. Pines, alders, and similar plants spread so readily in this region, that these bare hill-sides would assuredly be clothed thickly with a forest vegetation, thus replacing the forests which have been swept away, if there had been time enough for the purpose.

The immense area and great depth of these treeless drift formations would surely be regarded as requiring perhaps many centuries for deposit, but for the evidence which the botanical observations afford that the whole change must have taken place within very recent times".