ter, if the above explanation is correct, are caused partly by osmose, and partly by special secretive action, the cell-walls and outer coat of the body of the oyster corresponding to the walls of the alimentary canal in the human body. The forms of vital activity in the two cases are different, but osmose is concerned in both.

The main points here urged may be very briefly summarized:

1. In the floating of oysters for the market, a practice which is very general, and is also used for other shell-fish, the animals are either taken direct from the beds in salt water, and kept for a time in fresher (brackish) water before they are opened, or water is added to the shell-contents after they are taken out of the shell. When thus treated, the body of the animal takes up water and at the same time parts with some of its salts, while small quantities of the nutritive ingredients also escape. The oysters thus become more plump, and increase considerably in bulk and weight, but the quantity of nutritive material, so far from increasing, suffers a slight loss.

2. In the experiments here reported, the increase in bulk and weight was from one eighth to one fifth of the original amounts. This is about the same as is said to occur in the ordinary practice of floating or "fattening" for the market. According to this, five quarts of oysters in their natural condition would take up water enough in "floating" to increase their bulk to nearly or quite six quarts, but the six quarts of floated oysters would contain about one tenth less of actual nutrients than the five quarts not floated.

3. The gain of water and loss of salts are evidently due to osmose. The more concentrated solution of salts in the body of the animal, as taken from salt water, passes into the more dilute solution (fresher water) in which it is immersed, while a larger amount of the fresher water at the same time enters the body. But part of the exchange, and especially that by which other materials, carbohydrates, protein, etc., are given off in small quantities, is more probably due to a special secretory action.

4. The flavor of oysters is often much improved by the removal of the salts in floating, and they are said to bear transporting and to keep better. When, therefore, the oyster-man takes "good fat oysters " which "yield five quarts of solid meat to the bushel" and floats them so that "they will yield six quarts to the bushel," and thus has an extra quart, and that a quart of the largest and highest-priced oysters, to sell, he offers his customers no more nutritive material—indeed, a trifle less-in the six quarts than he would have done in the five quarts if he had not floated them. But many people prefer the taste of the floated oysters, and since they buy them more for the flavor than for the nutriment (at ordinary prices, the nutrients in oysters cost the buyer from three to five times as much as similar nutrients in the better kinds of meat), doubtless very few customers would complain if they understood all the facts. And considering that the practice is

very general and the prices are regulated by free competition, the watering of oysters by floating in the shell is, perhaps, less reprehensible than at first thought it might seem. This phase of the question, however, it is not the purpose of this article to discuss.

5. From the standpoint of chemical physiology the most interesting outcome of the experiments is the very interesting parallelism they show between the processes by which the salts and other materials pass from within the body to the surrounding medium and those by which the digested materials of the food in man and other animals are conveyed through the walls of the alimentary canal into the blood and lymph to serve their purposes in nutrition. In each case the process seems to be due in part to osmose (dialysis) and in part to a special function of the organs.

To recapitulate still more briefly: The oysters in "floating" in fresher water, for some hours after they were taken from the beds in salt water, as is commonly done in preparing them for the market, gained from one eighth to one fifth in bulk and weight by taking up water, but at the same time lost about one tenth of their nutritive material. They did this by processes essentially similar to those which go on in our own bodies, and by which the digested food passes from the alimentary canal into the blood, to be used for nourishment.

GEIKIE ON THE TEACHING OF GEOGRAPHY.*

G

BY FREDERIK A. FERNALD.

EOGRAPHY has been the last of the sciences which are studied in school to be affected by the modern demand that science shall be taught according to the scientific method. It is extremely important that this method of teaching the description of the earth should speedily become general, for most pupils study geography, and those who leave school at an early age may not otherwise obtain that quickening of the powers of observation and inference which the study of science gives.

Furthermore, to quote Professor Geikie, "Geography, in the wide and true sense of the word, offers admirable scope for this kind of training. It may be begun on the very threshold of school-life, and may be pursued in ever-increasing fullness of detail and breadth of view up to the end of that time. No other subject can for a moment be compared with it in this respect. It serves as common ground on which the claims of literature, history, and science may be reconciled." In order to aid teachers in leading their pupils into the study of

"The Teaching of Geography. Suggestions regarding Principles and Methods for the Use of Teachers." By Archibald Geikie, LL. D., F. R. S. London and New York: Macmillan & Co. Pp. 202. Price, 60 cents.

geography by the natural method, Professor Geikie has written a little manual, which broadly sketches the plan to be adopted. The following paragraphs embody the principal features of this plan :

To begin the teaching of geography with formal lessons on the shape of the earth, parallels, meridians, equator, poles, and the rest, is to start at the wrong end. To the average boy or girl of six or seven years these details have no meaning and no interest. Their introduction on the very threshold of geographical instruction is a characteristic feature of our system, or rather want of system, in this department of education. They are very generally placed at the beginning of our class-books, and being there, they form, as a matter of course, the subjects of the first lessons usually given in geography. An altogether inordinate value is set by us upon class-books. Instead of serving, as they ought, merely to furnish the text for the fuller and more interesting exposition of the teacher, these books are for the most part slavishly followed.

The lesson of the day too often consists in the repetition by rote of so many sentences or paragraphs from the class-book, which are seldom expanded or made more attractive and intelligible by elucidation on the part of the teacher. Such instruction, if it may be so called, is bad for the teacher and worse for the taught. It is especially pernicious to the children in the earlier stages of their geographical studies, for it tortures their memories and brings no compensating advantage. It fosters idleness and listlessness on the part of the teacher, who, instead of exerting his faculties to invest the subject with a living interest, becomes for the time a mere machine, mechanically acting within the limits prescribed in the class-book.

In dealing with the young we should try to feel ourselves young again, to see things as they are seen by young eyes, to realize the difficulties that lie in the way of children's appreciation of the world around them, to be filled with an abounding sympathy which subdues all impatience on our side, and calls out on the side of the children their confidence and affection. Mutual sympathy and esteem are a pledge of enduring success. To cement this bond of union between teacher and taught there should be no set tasks for some considerable time. The lessons ought rather to be pleasant conversations about familiar things. The pupils should be asked questions such as they can readily answer, and the answering of which causes them to reflect, and gives them confidence in themselves and freedom with the teacher. The objects in the school-room, in the play-ground, on the road to school, should be made use of as subjects for such questionings, with the aim of drawing out the knowledge acquired by the pupils from their own observation. Every question should be one which requires for its answer that the children have actually seen something with their own eyes and have taken mental note of it. The putting of such questions stimulates the observing faculty, and not unfrequently

gives a chance of distinction to boys and girls whose capabilities are not well tested by the ordinary lessons of school.

But, while laying his foundations broadly in this way and widening the knowledge of his pupils, the teacher will do well to keep clearly before him some definite goal toward which the discipline of the elementary stage is to lead up. Probably no object can be suggested more fitting for this purpose than the thorough comprehension of a map. The power of understanding a map, and getting from it all the information it can afford, is an acquisition which lies at the base of all sound geographical progress. Yet how large a proportion, even of the educated part of the community, have only a limited and imperfect conception of the full meaning and uses of a map !

There is happily now a growing recognition of the principle that adequate geographical conceptions are best gained by observations made at the home locality. The school and its surroundings form the natural basis from which all subsequent geographical acquirement proceeds. Upon a groundwork of actual observation and measurement the young mind is led forward in a firm and steady progress. The school-room and play-ground serve as units from which an estimate is gradually formed of the relative proportions of more distant objects and places.

During infancy we learn that things differ in size and in distance from us. How much they differ in these respects is found out more slowly, if indeed discovered at all. Among the peasantry many adults may be met with who have hardly advanced a step beyond the infantile stage of perception. And even among those who consider themselves educated, it is sometimes ludicrous to see how absolutely untrained they are to judge with even an approach to accuracy of the relative sizes and distances of things. One of the most useful lessons, therefore, in the elementary part of geographical instruction, is to accustom the pupils to appreciate differences of size and proportion by actual measurement. The most convenient unit of measure to start with is the length of a pace, while the school-room is the most convenient place to try the first experiments in mensuration. By multiplying the measurements they have taken at school, the pupils will appreciate how far it is from school to their homes, what distance separates their village or town from the next, what is the size of their parish or county, and so on to the country as a whole, and eventually to the dimensions of the earth itself, and of planetary space.

If want of accuracy in judging of the dimensions of things is a common failing, not less prevalent is want of accuracy in judging of their relative positions, or what is called orientation. We begin in infancy with the difference between our right and left hands, and recognize things and places as lying to the right or left of us. But many of us hardly get beyond this rudimentary stage. It is almost incredible how helpless even educated people often are if asked to tell

whether one place lies to the north or south of another. They know that in passing between them you go to the right or left, as the case may be, but there their power of localization ends. What is needed is greater quickness and precision in orientation, and this ought to be acquired from early training at school.

When some progress has been made in elementary geographical conceptions, the blackboard should be brought into increasing use. After the school-room, for example, has been paced, and its dimensions and proportions have been thus ascertained, its plan should be drawn on the board by the teacher, with the relative positions of door, windows, and fireplace. From this beginning, gradual steps may be taken until the pupils can themselves draw on the board and on their slates rough plans of the school and of the play-ground. At first it will be sufficient to aim only at a general resemblance of proportion. The great object is to teach the young minds to realize the relations between the actual boundaries and the artificial representations of them. To succeed in this is by no means so easy as might be thought; but success in it is absolutely necessary, and must be attained no matter at what expenditure of time and labor. When it has been achieved, efforts should next be made to depict the plan to scale, and with a nearer approach to correctness.

It is desirable to ascertain and arrange the conceptions that children already possess as to time. They know that day and night follow each other in unbroken succession. They further know that each day has a morning, a noon, and an evening. These and their other notions should be drawn from them by questioning, and the answers, corrected by the class (or by the master if no member of the class has the requisite information), should be methodically summarized and repeated in the simplest language, as the basis of actual experience from which the pupils are to advance to further acquisitions of knowledge.

In taking the school surroundings as the basis of instruction, the teacher will readily recognize that, while the principle of his method remains the same, its details must necessarily vary according to the circumstances of the locality. The two most obvious distinctions are those of town and country. In a town, illustrations of the political side of geography are most prominent; in the country, it is the physical side that especially invites attention. The teacher should from the first realize that some of the most valuable parts of the training his pupils can receive are not attainable within the walls of the class-room. Where practicable, he should himself take walks with his pupils, and direct their attention to the objects to be seen as they go. There are, no doubt, practical difficulties in the way of carrying out this method, but these are generally not insurmountable.

In all these lessons, the system of question and answer must be scrupulously followed. Anything approaching to a style of lecturing