An Introduction to Nature-study

An animal or a plant must be studied from several points of view before its manner of life can be understood in any real sense. It must, for example, be regarded, first, as a complicated piece of machinery, every part of which is beautifully fitted for the performance of a special duty; it must also be considered as an individual, having likes or dislikes—or at least tendencies—which are to some extent peculiar to itself; finally, it must be considered in its relation to other animals and plants, and to its surroundings. Field-work is especially concerned with the last of these methods of study—the observation of living things under natural conditions,—and this ought constantly to be borne in mind. To make nature-study a pretext for uprooting locally-rare plants and robbing birds’ nests is indefensible. The commonest plants are usually the most instructive, and afford ample material for the beginner’s experimental work; while the pleasure of finding and describing (perhaps photographing) a bird’s nest, and of keeping the eggs and young under observation, is something unknown to the mere collector of eggs. The life of both plant and animal is sacred in the eyes of every nature-student worthy of the name. At the same time, no sentimentality ought to prevent the destruction of undoubtedly noxious insects and weeds. In general, however, specimens should be killed only for the purpose of a leisurely examination of structure, which would otherwise be impossible, or to make needed additions to the teaching-collection of a school museum.

Generally speaking, collecting is of very doubtful value, except to experts. Insects and common plants may, however, be collected without scruple by the beginner, though it is worth remembering that the most perfect specimens of butterflies and moths are those reared in captivity from the eggs, larvae, or pupae.

The student is strongly recommended to make a sketch map of some small area to which he has easy access, and to record upon this the positions of features of special interest. Such a map may, in the first instance, be copied on an enlarged scale from an ordnance map of the neighbourhood, which may be obtained at the local free library. It will be advisable to duplicate the drawing by means of one of the many appliances for such work, and to keep one copy each for trees, flowering plants, birds’ nests, etc.—the position of each object, or of a well-defined group, being carefully marked by a small number (Fig. 237), and the reference, with the date, being filled in on the margin. The varying character of the ground—sandy, marshy, clayey, etc.—should be indicated by diagrammatic shading or colouring. By following this method the student will more clearly realise that different plants are dependent upon different conditions of soil, drainage, etc.; and that, e.g., plants at home on a bleak moor, in a hedge, in marshy land or in water respectively, are characteristically modified so that they can make the best of their special conditions of life. In this manner he will, almost unconsciously, gain wider views of the relationships which exist between the facts learned from his more detailed observations. It would be a distinct gain to biological science if field clubs also would adopt some such plan, each member undertaking to fill in upon his map information of the animal and plant life of the area allotted to him. The co-operation of various clubs, and the systematic arrangement of information thus obtained, would result in a store of knowledge of the highest value.

Many animals are so shy that they can only be approached with difficulty. In such cases it is especially necessary for the observer to move quietly and silently, and, when a favourable position is reached, to remain as motionless as possible, preferably with his back to the sun. If a field-glass can be obtained it will be of great assistance, but some practice will probably be required before it can be used easily.

It is well to start each ramble with some definite object of study in view—either trees, grasses, flowers, fruits, birds, caterpillars, or pond life, for example, and to be provided with pill-boxes, bottles, etc., according to circumstances. A notebook, pencil, pocket knife, and hand lens should, however, always be carried, and observations should be recorded on the spot.

Pond life.—Practically the only method of gaining a real knowledge of aquatic organisms is by the help of the aquarium. Specimens may be obtained by means of a net, or of a small wide-mouthed bottle tied to a stick. A pickle bottle is convenient for carrying home the material collected. The conditions of a natural pond should be imitated as closely as possible in the aquarium. At first, some little difficulty will probably be found in obtaining the necessary balance between the animals and plants of the aquarium. When this has been reached, it will only rarely be necessary to change the water, provided that dead or sickly specimens are promptly removed.

THE SCHOOL JOURNEY.

In the organisation of school journeys so much depends upon local conditions of various kinds, so much must of necessity be left to the initiative of the teacher, that it is manifestly impossible here to do more than enunciate certain general principles. In the first place, it should be borne in mind constantly that the primary object of the school journey is the cultivation of habits of thoughtful observation; and that the chief danger to be guarded against is that out-of-focus condition into which the mind, like the eye, inevitably falls when it is concerned with too many things at once. To obviate this danger the teacher should go over the route in advance, noting carefully the features, physical and otherwise, which afford material for observation and investigation by the class. The order in which these features may be best studied should be decided upon, and a scheme of several visits, each to be concerned with one special subject of study, can then be drawn up. Such a preliminary survey should suggest a plan by which every member of the class may be allotted a definite task—to find something or do something, or to solve some problem on the spot.

These principles may be best illustrated by a special example, but it will be obvious that the same ideas, with modifications in detail, may be applied in any district. The sketch-map (Fig. 237) illustrates a walk through Healey Dell, near Rochdale, Lancashire. The rocks which are exposed at various places along the route belong to the Carboniferous formation, and are composed of shale, coal, or millstone grit.

The object of the first journey will be in most cases to familiarise the class with the “lie of the land” and the most obvious features of the scenery. As a preparation, lessons should be given on the points of the compass and the various methods of finding the direction of the north. The simplest of these is by the use of the compass: it being remembered that the needle points about 16° to the west of true north. A second method depends on the fact that at noon the sun is in the south and that therefore (because the hour hand of a watch makes two revolutions in the twenty-four hours) the north and south line approximately bisects the angle between twelve and the hour hand, if the latter is pointed to the sun when the watch is horizontal. Incidentally, the method of finding the pole-star might be also explained to the class. Further, each pupil should be encouraged to find out how many steps he takes, on the average, in pacing a given measured distance. If the general direction of the walk is north and south, as in the example, it will be found best to begin the first journey at the south end (in this case from Shawclough Station), since to most children it is easier to conceive of a journey northward than in any other specified direction. Throughout the ramble constant reference should be made to the direction of the route and the relative positions of well-marked features of the landscape. The distances between certain points should be estimated, and, whenever possible, measured (by pacing), and notes made by the class. For example, from Shawclough to Ending the distances and directions are roughly: ¼-mile W.N.W., ⅓-mile N.N.W., ¼-mile E.N.E. In the first journey also the class should be made to notice where the ground slopes most and where least (the direction and angle of slope should be estimated in a few cases), and the names of neighbouring woods, farms, etc., should be learnt. The direction of flow of the river and the various bends in its course should also be noted, and reference made to the route by which, after joining those of other rivers, its waters ultimately reach the sea. Afterwards, the pupils should write an account of the journey and, in the higher classes, should be encouraged to draw a sketch-map, however crude, from memory.

Before the second journey each pupil should be provided with a blank sketch-map of the route. This may, in the first instance, be copied or traced from the six-inch Ordnance Map, and then duplicated in large numbers. Only the route and river, and a few of the more conspicuous landmarks, should be indicated on the maps as given to the class: details should be filled in, on the spot, by the pupils. The object of the second journey may conveniently be the study of the river and its work, and for this purpose it will be advisable to follow the stream in the direction of its flow. Variations in the speed of the current, and in the width of the stream and the hardness of the rocks or banks between which the water flows, should be noted, and the relations between cause and effect elicited by questioning. The hardness of the rocks at 4 has prevented the channel from being widened to a greater extent by the water, and accounts for the rapidity of the flow. A glass of water collected here is found to contain much suspended gravel. The considerable loss of weight of bodies in water is noteworthy, as explaining the great size of the stones which may be transported by rivers. The scouring action of such stones is shown in the fine “potholes” at 4 and below the waterfall (Fig. 238) at 10, and has resulted also in the quaint stone portico of the “Fairies’ Chapel” under the right (west) bank of the river at 7. Again, the difference in the rates of erosion of hard and soft rocks has had much to do with forming the waterfalls at 5 and 10. Where the stream is wider and the flow slower (as at 6 and 9, and below 10), may be noticed sand and mud deposits; and where the stream makes a bend it is found that the slowest flow and the maximum deposit are on the convex bank; while the concave bank is worn almost vertical (as at 6 and other places) by the swifter rush of the water, and may be undercut to such an extent as to cause the bank to give way. In this manner a river is constantly changing its course. The weir at 13, and the old water-wheel still to be seen in the ruined mill below, suggest remarks on the motive power of water, and on the circumstances which may cause the old industries of a district to be superseded by new ones. Along the rest of the route the bed of the river is less steep and its banks exhibit less variation, but they still afford plenty of material for study. The railway viaduct at 14 and an aqueduct at 16 suggest at least a casual reference to the derivation of the terms. Before the pupils are asked to write a “composition” on the ramble, a revision lesson on the features noticed should be given, and the accuracy of the entries on the sketch-maps checked by comparison with an enlarged map drawn by the teacher, or with a large “parish plan” of the Ordnance Survey, on the scale of 25.3 inches to the mile.

It will be well to devote two or more journeys to the study of the trees along the route. One journey should be taken in the spring, before the leaves are out, and another in the summer, when the foliage is well developed. It is far better to study three kinds of trees in some detail than to risk confusion at the beginning by attending to a dozen. In Healey Dell the commonest trees are beech, oak, and sycamore, and these serve admirably as an introduction to tree lore. If the first tree-journey be taken in the summer, the leaves of some three abundant species should be compared and contrasted, and each pupil should secure good specimens, to be drawn and preserved afterwards. The presence of a little bud in the “axil” (the upper angle between leaf and twig) of most of the leaves should be pointed out by the teacher; and since the arrangement of the buds (and therefore of the subsequent branches of the twig) thus depends on the positions of the leaves, this last point is of considerable interest. In the sycamore, the leaves are in pairs at right angles to each other; in the beech and oak they are single and alternate, but much more crowded together in the oak than in the beech. The bark of the three trees is equally distinctive, and with the method of branching (obscured when the foliage is thick) serves to identify the trees from a distance in the winter. In winter and spring the interest of a tree is centred in its buds, and there are few things which more richly repay study. In spring, attention should also be given to the flowers—generally arranged in catkins—of common trees. Separate sketch-maps should be used as records of the positions of the more notable trees or plantations along the route. Any tendency to vandalism on the part of the pupils by tearing off branches should, of course, be sternly repressed; especially interesting twigs should, on occasion, be cut off by the teacher only, for later study.

There is much diversity of opinion as to the way in which flowers may be best studied in a limited number of school journeys. In most cases it will perhaps be impracticable to attempt more than teaching the names and calling attention to the habitat of the commonest. This, though a necessary introduction to the subject, tends to degenerate into a mere exercise of the memory, and in itself possesses little educational value. It should be supplemented by a detailed examination of a typical flower—say a buttercup—and by the explanation of the work of each part. Once the pupil has understood that the single duty of a flower is the production of healthy seeds, and has been led to notice how, by the aid of ingenious devices, the up-to-date plants have learnt to call in the aid of insects, while the more conservative families still rely on the aid of the wind, he will be eager to discover for himself “how the thing works.” With young children it is folly to attempt any but the very broadest principles of classification of flowers; but quite young children can appreciate the advance from flowers without petals, through flowers with separate petals, to those with petals united to form a tube (thus restricting the nectar more and more to “useful” insects); and so understand the advantage which a primrose has over a buttercup, and a buttercup over an oak flower.

At least one journey should be given, in the autumn, to the study of the dispersion of fruits and seeds. The pupils should provide themselves with empty match-boxes or chip pill-boxes. In this ramble the class may with advantage be divided into four groups. Group A will collect examples of fruits and seeds which are dispersed by the wind; Group B, of fruits which by means of hooks or otherwise become attached to the hides of grazing animals, and are carried far from the place where they grow; Group C will collect fruits which tempt animals to eat them for the sake of sweet pulp (in these cases the pupils should find out a how the fruit is made conspicuous, b how the seeds themselves are protected from being injured by the animals); while Group D will search for specimens of plants which sow their own seeds.

There still remains abundant material for study in this walk, and mention only can be made of the sticklebacks, frog-spawn, snails, caddis-worms, dragon fly larvae, blood-worms—of the “things creeping innumerable, both small and great beasts”—which have been found in the river, ponds, and wells along our route, and have been used to stock the aquarium; of the rabbits and birds; of the nests of ants and wild bees and wasps; of a certain blackberry bush (31) rich in interesting leaves; and of a thousand and one other things which, under the guidance of a judicious leader, may well be the means of teaching children to see what they look at and to think about what they see. For this is the first and last object of the school journey.