problems of animal psychology. It has received the name of "the homing instinct," and is regarded by some naturalists as constituting an additional sense. The dog seems usually to be more ready than the cat to follow his master in a change of home, and to reconcile himself to the new place, but this may be because he stands in a different relation toward him. The dog is sure of at least one fast friend wherever he lives, while the cat can not always reckon even upon that. In many families, where she is tolerated, as, according to Buffon, only because she is less objectionable than the rats and mice, she has no one to caress her or show affection to her. In this case, when her situation is barely endurable, she naturally fixes her attachment on the place where she has found cozy retreats and knows all the hunting-grounds, rather than upon persons who have given her no consideration, and of whom she perhaps stands in fear. Whether the cat will in the long run prefer its old home, deserted or inhabited by strangers, to a new home, along with the persons it has been accustomed to meet, may depend very much upon the treatment it has received from those persons. My cat was removed three times in ten years; and, aside from the temporary embarrassment caused by finding herself in a strange place, readily adapted herself to the new quarters, and showed no disposition to go back to the old haunts. Lindsay, in

FIG. 11.-FINELY MARKED TORTOISE-SHELL CAT. By permission, from Harrison Weir's Our Cats and all about Them. Published by Houghton, Mifflin & Co., Boston and New York.

his Mind in the Lower Animals, refers to cases of cats following their masters from house to house, from place to place, and accompanying them on visits to other people's residences, as unconcernedly as a dog. Wood tells of a family on the coast of Scotland who removed to the opposite shore-sailing around instead of crossing the country-leaving their cat with a neighbor. But the animal followed them, and found them in some way, presenting itself after a few weeks at their door, "weary, ragged, and half starved." It had left its old home and gone out into the unknown to seek the family with whom it had lived. A case pre

cisely similar, except as to the local topography, is related in Chambers's Journal, of a cat in a military chaplain's family at Madras. This animal also, having found its old friends on the other side of the city, several miles from their former home, went back and brought her kitten. Some of the incidents bearing upon this feature have an aspect of eccentricity. The young cat of a neighbor of the writer's disappeared from the house and was not found or heard of for six months. At the end of that time it returned and made itself at home at once, but grown and so changed that, though its familiarity was remarked upon as singular, it was not recognized till its identity was accidentally established by the discovery of a peculiar though obscure mark. Dr. A. Corriveau tells in the Revue Scientifique of a cat which was lost in a similar way. Five months afterward it was found in the house by the side of its companion, travel-soiled but plump, and recognizable by a red spot on its forehead. It had a very pleasant visit with its old mate and friends for a week, and then disappeared as unaccountably as it had done before. It is told in the Life of Sir David Brewster, by his daughter, that a cat in the house entered his room one day and made his friendship in the most affectionate manner-"looked straight at him, jumped on his knee, put a paw on each shoulder, and kissed him as distinctly as a cat could." From that time the philosopher himself provided her breakfast every morning from his own plate, till "one day she disappeared, to the unbounded sorrow of her master. Nothing was heard of her for nearly two years, when Pussy walked into the house, neither hungry nor thirsty nor foot-sore-made her way without hesitation to the study-jumped on my father's knee-placed a paw on each shoulder-and kissed him exactly as on the first day."

These incidents pertain to only one of the human-like traits that have been named as to be found in cats. The study to which they introduce us is an alluring one, and opens the more expansively the further we proceed in it.

PROF. MENDELEJEFF, in his Royal Institution lecture, found an analogy between the unseen world of chemical changes and the visible world of the heavenly bodies. Our atoms, he said, form distinct portions of an invisible world, as planets, satellites, and comets form distinct portions of the astronomer's universe; "our atoms may therefore be compared to the solar system, or to the systems of double or of single stars; for example, ammonia may be represented in the simplest manner by supposing the sun nitrogen, surrounded by its planets of hydrogen, and common salt may be looked upon as a double star formed of sodium and chlorine. Besides, now that the indestructibility of the elements has been acknowledged, chemical changes can not otherwise be explained than as changes of motion; and the production by chemical reactions of galvanic currents, of light, of heat, of pressure, or of steam-power, demonstrates visibly that the processes of chemical reaction are inevitably connected with enormous though unseen displacements, originating in the movements of atoms in molecules."

AT

RECENT GLACIAL WORK IN EUROPE.

BY MRS. K. B. CLAYPOLE.

T the recent meeting of the British Association at Newcastle, Prof. James Geikie opened the Section of Geology with a summary of the results obtained during the last few years by continental glacialists. Sketching the steps by which the iceberg theory has been abandoned by German and Swiss geologists, he dwelt on certain features of the drifts of the peripheral areas, which for some time were hard to account for by land-ice. Of these, the bedded deposits occurring so frequently in the bowlderclays of the peripheral regions, and the occasional silty and uncompressed character of the clays themselves, remained unexplained until a clew was found to their origin in the geographical distribution of the clays in which they occur. These stony clays, of inconsiderable thickness in Norway, the higher parts of Sweden, and in Finland, reach a thickness of about forty-three metres in southern Sweden, and eighty metres in the northern parts of Prussia; and in Holstein attain a depth of one hundred and twenty to one hundred and forty metres, and still greater depths in Hanover, Mark Brandenburg, and Saxony. The aqueous deposits associated with the stony clays also gradually acquire more importance as they are followed from the mountainous and highlying tracts to the low ground, until, along the southern margin of the drift area, the "diluvium" appears to consist of aqueous accumulations alone. The explanations of these facts by German geologists have been summed up recently (1884) by Dr. Jentzsch, from whom Prof. Geikie quoted enough to show that they are quite in accordance with the views long held by glacialists elsewhere.

The general conclusions reached by continental glacialists, and summarized by Prof. Geikie, are:

1. Before the invasion of northern Germany by the inland. ice, the low grounds bordering on the Baltic were overflowed by a sea which contained a boreal and arctic fauna.

2. The next geological horizon in ascending order is that which is marked by the glacial and fluvio-glacial detritus of the great ice-sheet which flowed to the foot of the Harz Mountains, and has been traced by the occasional presence of rock-striæ and rochesmoutonnées, of bowlder-clay and northern erratics, rather than by recognizable terminal moraines.

3. A well-marked temperate fauna and flora marks the interglacial beds which follow, and which, in their geographical distribution and the presence in them of such forms as Elephas antiquus, Cervus elephas, and C. megaceros, and a flora compar

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 Palæolithic 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

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