able to that now existing in northern Germany, justify geologists in concluding that this era was one of long duration, and characterized in Germany by climatic conditions apparently not less temperate than those that now obtain.

4. To this well - marked interglacial era succeeded a second overflow of Scandinavian inland ice, confined to a region much narrower than that covered by the first. Its boundaries are shown not only by the geographical distribution of the youngest bowlderclay, but by the direction of rock-striæ, the trend of erratics, and the position of well-marked moraines.

Concerning the ground-moraines of the Alpine lands of central Europe, the only question that has recently given rise to much discussion is the origin of the materials themselves. The observations of able investigators appear to Prof. Geikie to have demonstrated that these materials have been derived, in chief measure, from the underlying rocks by the erosive action of the ice that overflowed them. German geologists are not agreed upon this much-debated question of glacier-erosion-a few still maintaining that glaciers have little or no eroding power. But where the evidences of erosion have been studied over a wide region, from which the ice has completely disappeared, rather than at the lower ends of existing glaciers, some of the strongest opponents of glacier-erosion have been compelled to go over to the other camp. As an example, Prof. Geikie quoted Dr. Blaas, who, through his observations on the glacial formations of the Inn Valley, has recanted his former views and become a formidable opponent of the very theory which he once upheld. To his books and to memoirs by Penck, Brückner, and Böhn, and especially to the chapter on glacier-erosion by the lastnamed author, Prof. Geikie refers those who may be anxious to know the last word on this question.

Observations by Drs. Brückner and Penck have led to the opinion that the loess is of interglacial age. Examining a wider range of evidence, Prof. Geikie has little doubt that the loess belongs to no particular horizon, though it must be considered strictly a Pleistocene accumulation. Concerning its mode of formation he discussed the various theories advanced, and gave it as his opinion-an opinion formed from what he has himself seen of the loess in various parts of Germany, from reading, and from conversation with those who have worked over loess-covered regions-that it is for the most part of aqueous origin, formed in the slack waters of the great rivers, and in the innumerable temporary lakes which occupied or partly occupied many of the valleys and depressions of the land. Probably some may have been derived from the denudation of bowlder-clay, some from "rainwash," while much of the so-called Bergloess with its abundant land-shells, and its generally unstratified character, owes its origin to rain, frost, and wind. Admitting that some of the loess of the lower grounds may have been reworked by the same agents, Prof. Geikie found no evidence in the facts adduced by German geologists of a "dry-as-dust" epoch having obtained in Europe during any stage of the Pleistocene period.

Within recent years the fossils of the loess have received close attention, and through them so much knowledge has been gained of the various modifications experienced by Pleistocene organisms that, taken with other evidence of interglacial conditions, there is little room to doubt that this period was characterized by great changes of climate. How often arctic, steppe, prairie, and forest faunas and floras have replaced each other is yet a matter of dispute. The occurrence of fossiliferous deposits intercalated among glacial accumulations throughout all the glaciated tracts of Europe show that however many advances and retreats of the ice there may have been, they were on a gigantic scale characterizing all the glaciated areas.

The bearing of the establishment of at least two eras of glaciation on the position of Paleolithic man was pointed out by Prof. Geikie. The mere occurrence of glacial deposits underneath implement-bearing beds no longer proves these latter to be post-glacial. The horizon of glacial accumulations underlying Palæolithic gravels must now be determined by ascertaining their relative position; and it is a remarkable fact that the bowlder-clays which occur beneath such old alluvia belong, without exception, to the earlier stages of the Glacial period. In 1871-72 Prof. Geikie published a series of papers in the Geological Magazine, maintaining that the alluvial and cave deposits must be assigned to preglacial and interglacial times, and in chief to the latter. Evidence was adduced to show that during the last stage of the Glacial period man lived contemporaneously with a northern and Alpine fauna, in such regions as southern France; and that Palæolithic man and the southern mammalia never revisited northwestern Europe after extreme glacial conditions had disappeared. Prof. Geikie at the same time colored a map to show at once the areas covered by the glacial and fluvio-glacial deposits of the last Glacial era, and the districts in which the implementbearing and ossiferous alluvia had been found; and this clearly brought out that the latter never occurred at the surface within the regions occupied by the former. Similar evidence has been recently obtained by continental geologists; and a map published by Dr. Penck in 1884, showing the areas covered by the earlier and later glacial deposits in northern Europe and the Alpine lands, and indicating at the same time the various localities where Palæolithic finds have occurred, does not give a single

VOL. XXXVII.-8

locality within the regions covered by the accumulations of the last Glacial era. So greatly are students of the Pleistocene ossiferous beds influenced by what is known of the interglacial deposits and their organic remains, that many do not now hesitate to correlate with those beds the old ossiferous and implement-bearing alluvia which lie altogether outside of glaciated regions. In France, where the relation of Pleistocene alluvia has been especially canvassed, these alluvia have been also included among interglacial deposits. M. Boule also, in the Revue d'Anthropologie, 1889, correlates the Palæolithic cave and river deposits of France with those of other countries, and shows that they must be of interglacial age. He is satisfied that in France there is evidence of three glacial and two well-marked interglacial eras. The oldest of the Palæolithic stages of Mortillet culminated during the last interglacial era, while the more recent Palæolithic stages coincided with the last great development of glacier ice. The Palæolithic age, so far as Europe is concerned, came to a close during this last cold phase of the Glacial period.

Interesting as is the development of the climatic and geographical changes of which our Palæolithic predecessors were the witnesses, the clearing up of the history of Pleistocene times is not the only end that workers in this field have in view. Prof. Geikie, therefore, closed his address with a hope that the definite knowledge of the conditions of the Pleistocene period and of the causes which gave rise to them would lead to the better understanding of the climatic conditions of still earlier ages; the success with which other problems have been attacked by geologists forbidding him to doubt that ere long we shall have done much to dispel some of the mystery still enveloping the question of geological climates.

IT

THE BOTANIC GARDENS AT KEW,

BY FREDERIK A. FERNALD.

T is now about two hundred years-the exact date is not known-since Lord Capellaid out the garden that has become a scientific institution of world-wide fame and influence. Switzer says, in his quaint Ichnographia Rustica, 1718, "The earliness with which this lord appeared in gardening merits a very great place in my history, and a better pen than mine to draw it." On the death of Lord Capel, in 1696, the estate of Kew House, including the garden, passed into the hands of his son-in-law, who added to its importance for a while by making it the headquarters of English astronomy. It was afterward leased by Frederick, Prince of Wales, son of George II. The garden was made a scientific establishment what they called a "Physic Garden" in those daysby the widow of Frederick, the dowager Princess Augusta, under the advice of the Earl of Bute. She employed William Aiton to direct the scientific work, and Sir William Chambers to superintend the decorative gardening. "Science will ever be grateful to the one," says a writer in The Saturday Review,* "and Taste will never forgive the other while his constructions remain." In 1768 Sir John Hill published a catalogue of the plants at Kew. There were fifty ferns, about six hundred trees and shrubs, and several thousands of herbaceous plants. The list was not greatly lengthened twenty-one years after, when Aiton issued the Hortus Kewensis with the aid of Dr. Solander. But the collections made by Sir Joseph Banks in Captain Cook's famous voyage were deposited here; then those of Robert Brown and Allan Cunningham, who had accompanied Captains Flinders and King respectively to Australia; then the plants of Brazil and the Cape of Good Hope, gathered by Messrs.. Bowie and Masson; those of Caley, and Ker, and Menzies, and a host of smaller collections. In 1810 William Aiton the younger published a new edition of his father's work, which contained nearly ten thousand descriptions. About 1789 the estate was bought by George III, who devoted much of his leisure to its improvement. But evil days followed the death of Sir Joseph Banks, in whom Kew had a friend at court. For all Aiton could do, the gardens sank into neglect, and in 1838 it was proposed to disestablish and disendow them. A protest was raised, and, after further consideration, the gardens were surrendered by the crown and became a national establishment in 1840. Sir W. J. Hooker was appointed director in the following year. Kew has been fortunate in having had few changes in directors. It was in charge of William Aiton from 1759 to 1793; of William Aiton, Jr., from 1793 to 1840; Sir W. J. Hooker was director from 1841 to 1866; his son, Sir Joseph D. Hooker, from 1866 to 1886; and to him has succeeded Mr. W. T. Thiselton Dyer.

Under the directorship of Sir W. J. Hooker the Royal Botanic Gardens rapidly advanced in importance. During his term of office a report of the Progress and Condition of the gardens was made annually. This was superseded in 1883 by a monthly Bulletin of Miscellaneous Information. The early reports of Sir William Hooker are interesting, besides their historic and scientific value, for the evidence they give of his sturdy, ceaseless battles with the Treasury. The director is pathetic, indignant, and argumentative by turns, and one way or another he contrived to worry on till better times. In 1844 Sir William took the first important step of his administration by petitioning for a grant of the Royal Fruit House, which he offered to fill with his private collection of plant products. It was allowed in 1847, and thus the Museum of Economic Botany had its origin. This branch of the establishment now occupies three buildings. Every tree and plant which is known to serve a useful purpose is represented there, with illustrations of the manner of its employment, if possible. While the collection is very popular with the holiday visitor who comes only to be entertained, any one can understand its serious value to an ingenious and thoughtful mechanic or manufacturer. The Museum of Timber is largely used already. Cabinet-makers and furniture manufacturers quite recognize by this time what a store of hints for their craft is garnered here. The utility of the economic section, moreover, is by no means confined to the inhabitants of the British Isles. From every quarter of the globe samples of new products are sent for examination and report.

So long ago as 1815 an Herbarium and Botanical Library had been projected at Kew. George III, doubtless persuaded by Sir Joseph Banks, even raised a building for the purpose. After Sir Joseph's death, however, the scheme lapsed, and the building was granted to the King of Hanover. On his decease, Sir William Hooker urged the fulfillment of the old design, and his petition was granted when Mr. Bentham and Dr. Bromfield bequeathed their collections to the nation. The Herbarium of Kew is the largest in the world, and by far the most useful, because it is also most admirably arranged. The number of specimens in it is not on record. At Sir William Hooker's death, twenty-four years ago a rough estimate made the number a million, exclusive of duplicates. The written catalogue fills two gigantic volumes, and has to be continually posted up, for the collection increases by twenty thousand or so yearly. The dried plants in their portfolios stand in cases, and all are arranged upon the system of Sir Joseph Hooker's great work, the Genera Plantarum. The student has only to give the number attached to any genus in that book, and the case is unlocked and the portfolio laid before him in a moment. There are no formalities to check the young scholar here. He has but to present his credentials to Prof. Oliver, keeper of the herbarium, sign his name, and get to work. There are interesting features at every step of this noble collection, fascinating bits of history connected with every group of cases which bears the name of some distinguished botanist, the fruits of whose lifelong labor are stored here. Of all these, perhaps the herbarium of Dr. Lindley is the most attractive. It occupies only four small cabinets, but the contents will surpass the visitor's utmost expectations. On the lower floor is preparing the catalogue of all plants