Читать книгу Notes on Collecting and Preserving Natural-History Objects - Various - Страница 3

COLLECTING AND PRESERVING.

I.

GEOLOGICAL SPECIMENS.

By J. E. Taylor, F.L.S., F.G.S.

The great end of natural-history reading should be the development of a love for the objects dwelt upon, and a desire to know more about them. This can only be brought about by such practical acquaintance as collecting and preserving them induces. At the same time we should be sorry to see our young readers degenerate into mere collectors! It is a great mistake to suppose, that because you have a full cabinet of butterflies, moths, or beetles, therefore you are a good entomologist; or that you may lay claim to a distinguished position as a geologist, on account of drawers full of fossils and minerals. But this is a mistake into which young naturalists frequently fall. We have seen people with decided tastes for these studies never get beyond the mere collecting. In that case they stand on a par with collectors of postage-stamps. Nor is there much gained, even if you become acquainted with English, or even Latin, names of natural-history objects. Many people can catalogue them glibly, and never make a slip, and yet they are practically ignorant of the real knowledge which clusters round each object, and its relation to others. Both Latin and English names are useful and even necessary; but when you have simply learnt them, and nothing more, how much wiser are you than before? No, let the learning of names be the alphabet of science—the means by which you can acquire a further knowledge of its mysteries. It would be just as reasonable to set up for a literary man on the strength of accurately knowing the alphabet, as to imagine you are a scientific man the moment you have learned by heart a few scores of Latin names of plants, fossils, or insects! Let each object represent so much knowledge, to which the very mention of its name will immediately conjure up a crowd of associations, relationships, and intimate acquaintances, and you will then see what a store of real knowledge may be represented in a carefully-arranged cabinet.

The heading of the present articles will have indicated the subject chosen for brief treatment. We shall never forget the influence left by reading such charming and suggestive books as Mantell's 'Medals of Creation,' many years ago. Our mind had been prepared for the enthusiasm which this little book produced by the perusal of Page's 'Introductory Text-book,' Phillips's 'Guide to Geology,' and several others of a similar character. But we know of none which impels a young student to go into the field and hammer out fossils for himself, like Dr. Mantell's works. It is impossible not to catch the enthusiasm of his nature. The first place we sallied out to, on our maiden geological trip, was a heap of coal-shale, near a pit's mouth, in the neighbourhood of Manchester. Our only weapon was a common house hammer, for we then knew nothing of the technical forms which geological fancy so often assumes. We had passed that same heap of coal-shale hundreds of times, without suspecting it to be anything more than everybody else considered it viz. a heap of rubbish. Why that particular spot was selected, we cannot now say. We had seen illustrations of carboniferous plants, shells, &c., in books, but we seemed to imagine their discovery could only be effected by scientific men, and that it required a good deal of knowledge before one should attempt to find them. Suffice it to say we made the pilgrimage to the coal-shale heap in pretty much the same mind as we should expect to get the head prize in some fine-art drawing. The humble hammer was put into use, for a brief time without much effect, as we could hardly have commenced on a more barren kind of shale than we had chanced to hit upon. We imagined we could perceive traces of leaves and slender stems, but were afraid to trust our eyes. At any rate, there was nothing definite enough to raise our enthusiasm. But by-and-by, as the hammer kept cleaving open the thin leaf-like layers of shale, there appeared a large portion of that most beautiful of all fossil plants, the Lepidodendron. Those who are familiar with this object, with its lozenge-shaped markings running spirally up the stem, will readily understand the outburst of pleasure which escaped our lips! That was the first real fossil—a pleasure quite equivalent to that of landing the first salmon. How carefully was it wrapped in paper, and carried home in the pocket! There never was, and never will be, another fossil in the world as beautiful as that insignificant fragment of Lepidodendron.

We have seen a good many converts made to geology in a similar manner, since first we laid open to the light this silent memorial of ages which have passed away. Let a man have ever so slight acquaintance with geology, and give him the chance of hammering out a fossil for himself, and the odds are you thereby make him a geologist for life. There is something almost romantic in the idea that you are looking for the first time, and have yourself disentombed the remains of creatures which probably lived scores of millions of years ago! We would strongly advise our readers, therefore, not to fall into the error of supposing that fossil-hunting belongs to highly-trained geologists. On the contrary, it is by fossil-hunting alone that you can ever hope to be a geologist yourself. Another mistake often made, is that of supposing these rich and interesting geological localities are at a distance. It seems so hard to suppose, after reading about typical sections, &c., that under your very feet, in the fields where you have so often played, there occur geological phenomena of no less interest. But it is actually surprising what evidences of our earth's great antiquity, in the shape of fossils, &c., may be studied and obtained in the most out-of-the-way and insignificant places.

You say you have no rocks in your neighbourhood—nothing but barren sands, or beds of brick-earth or clay. Well, go to some section of the latter, exposed, perhaps, in some tarn or stagnant pond in a turnip-field. You examine the sides, and what do you see? Nothing, but here and there a boulder-stone sticking out. Well, be content with that. You said you had no rocks in your neighbourhood; how, then, has that boulder, which is a rounded fragment of a rock broken off from somewhere—how has it come there? Here is a poser at once. Examine it, and you will perhaps see that its hard surface is polished or scratched, and then you remember the theory of icebergs, and feel astonished to think that you hold in your hand an undeniable proof of the truth of that theory. Those very scratchings could have been produced in no other way; that foreign fragment of a rock now only to be found on some distant mountain-side could have been conveyed in no other manner. Not content with the exterior examination, you break the boulder-stone open, when you may chance to find it is a portion of silurian, carboniferous or oolitic limestone, and that it contains fossils belonging to one of those formations. Here is a find—an object with a double interest turning up where you never expected to discover the slightest geological incident! You examine other boulders, and find in them general evidences of ice-action in their present re-deposition, and most instructive lessons as to the nature of rocks of various formations, from the granite and trap series to the fossiliferous deposits. In fact, there is no place like one of these old boulder-pits for making oneself acquainted with petrology, or the nature of stones.

Fig. 1. Pocket Trimming-hammer.

Fig. 2. Duck's-head Hammer.

And now, as to the tools necessary to the young geologist. First of all, he cannot take too few! It is a great mistake to imagine that a full set of scientific instruments makes a scientific man. The following hammers, intended for different purposes, ought to be procured. Fig. 1 is an exceedingly useful weapon, and one we commonly use, to the exclusion of all others. It is handy for breaking off fragments of rock for examination; and, if fossils be included in them, for trimming the specimens for cabinet purposes. As a rule, however, field geologists are always divided over the merits of their hammers, some preferring one shape and some another. Fig. 2 is generally used for breaking up hard rocks, for which the bevel-shaped head is peculiarly adapted. It is usually much heavier than the rest, and is seldom used except for specific purposes. If our readers are inclined to study sections of boulder clay, and wish to extract the rounded and angular boulder from its stiff matrix, they cannot do better than use a hammer like Fig. 3. This is sometimes called the "Platypus" pick. Both ends can be used, and the pick end is also good for working on soft rocks, like chalk. A little practice in the field will teach the student how to use these tools, and when, much better than we can describe on paper. The hammers can be obtained from any Scientific instrument manufacturer, or from any of the dealers in geological specimens. We have found that the best hammers for usage, however, were to be made out of an old file, softened and well welded, rolled, and then hammered into a solid mass. If properly tempered a hammer made in this fashion will last you your life.

Fig. 3. "Platypus" Pick for clay, &c.

So much for the rougher weapons of geological strife. Next, be sure and provide yourself with thick-soled shoes or boots. Geological study will take you into a good many queer places, wet and dry, rough and smooth, and it is absolutely necessary to be prepared for the worst. Patent leather boots and kid gloves are rarely worn by practical geologists. And we have heard it remarked at the British Association meetings, that they could always tell which members belonged to the Geological Section by their thick-soled boots. A similar remark applies to clothes. The student need not dress for the quarry as he would for the dining room. Good, strong, serviceable material ought to be their basis.

Secondly, as to the student's comforts and necessaries. These are generally the last thing an ardent naturalist thinks about. For ourselves, however, we give him ample leave to provide himself with pipe and tobacco, should his tastes lie in that direction. We never enjoyed a pipe half so much as when solitarily disinterring organic remains which had slumbered in the heart of the rock for myriads of ages. As to the beer, we can vouch that it never tastes anything like so good as during a geological excursion.

We have found the leathern bags sold for school-book purposes to be as handy to deposit specimens in, during a journey, as anything else. They have the merit of being cheap, are strong, and easily carried. If not large enough, then get a strong, coarse linen haversack, like that worn by volunteers on a field day. Paper, cotton wadding (not wool), sawdust for fragments of larger fossils, intended to be repaired at home, wooden pill-boxes, and a few boxes, which may be obtained from any practical naturalist, with glass tops, are sufficient "stock-in-trade" for the young geologist. The wadding does not adhere to the specimens as wool does, and the glass-topped boxes are useful, as it is not then necessary to open a box and disinter a delicate fossil from its matrix in order to look at it. Add a good strong pocket lens, such as may be bought for half-a-crown, and your equipment will be complete. If you intend to study any particular district, get the sheets published by the Geological Survey. These will give you, on a large scale, the minute geology of the neighbourhood, the succession of rocks, faults, outcrops, &c. In fact, you may save yourself a world of trouble by thus preparing yourself a week or so before you make your geological excursion. The pith of these remarks applies with equal force if you purpose, first of all, to examine the neighbourhood in which you live. Don't do so until you have read all that has been written about it, and examined all the available maps and sections. This advice however, applies more particularly to geological examination of strata. If you are bent chiefly on palæontological investigation, that is, on the study of fossils, perhaps it will be best just to read any published remarks you may have access to, and then boldly take the field for yourself. In addition to a hammer, we would advise the young student to take a good narrow-pointed steel chisel, and a putty-knife. The former is very useful for working round, and eventually obtaining, any fossil that may have been weathered into relief. The latter is equally serviceable for clayey rocks or shales.

In arranging the spoils of these excursions for the cabinet, a little care and taste are required. We will suppose you to possess one of those many-drawered cabinets which can now be obtained so cheaply. Begin at the bottom, so that the lowest drawers represent the lowest-seated and oldest rocks, and the uppermost the most recent. If possible, have an additional cabinet for local geology, and never forget that the first duty of a collector is to have his own district well represented! A compass of a few miles will, in most cases, enable him to get a store of fossils or minerals which cannot well be obtained elsewhere. Supposing he is desirous of having the geological systems well represented, he can always do so by the insertion of such paragraphs as those which appear in the Exchange columns of 'Science Gossip.' It is by well and thoroughly working separate localities in this fashion that the science of geology is best advanced. You hear a good deal about the "missing links," and it is an accepted fact that we, perhaps, do not know a tithe of the organic remains that formerly enjoyed life. Who knows, therefore, but that if you exhaust your district by the assiduous collection of fossils, you may not come across such new forms as may settle many moot points in ancient and modern natural history? The genuine love of geological study is always pretty fairly manifested in a student's cabinet. Science, like charity, begins at home. It impels a man to seek and explain that which is nearest to him, before he attempts the elucidation of what really lies in another man's territory!

It is not necessary that the student should waste time in the field about naming or trying to remember the names of fossils, &c., on the spot. That can be best done at home, and the pleasure of "collecting" can thus be spun to its longest length. Box them, pack them well (or all your labour is lost), and name them at home. Or supposing you do not possess books which can assist you in nomenclature, carry your fossils or minerals, just as you found them, to the nearest and best local museum, where you will be sure to see the majority of them in their proper places and with their proper names. Copy these, and when you arrange your specimens in the cabinet, either get printed cards with the following headings—

Genus_____________________________________ Species___________________________________ Formation_________________________________ Locality__________________________________

(which can always be obtained at a cheap rate from the London dealers), or else set to work and copy them yourself in a good plain hand, so that there is no mistaking what you write. As far as possible, in each drawer or drawers representing a geological formation, arrange your specimens in natural-history order—the lowest organisms first, gradually ascending to the higher. By doing so, you present geological and zoological relationship, so that they can be taken in at a glance. You further make yourself acquainted with the relations of the fossils in a way you never would have done, had you been content to huddle them together in any fashion, so that you had them all together. Glass-topped boxes, again, are very useful in the cabinet, especially for delicate or fragile fossils, as people are so ready to take them in their hands when they are shown, little thinking how soon a cherished rarity may be destroyed, never to be replaced. Pasteboard trays, made of stiff green paper, squared by the student according to size, can also be so arranged as that the drawer may be entirely filled, and so the danger of shaking the contents about may be removed. Each tray of fossils ought to have the above-mentioned label fastened down in such a way as that it cannot by accident get changed by removal.

The spring and summer time are fast approaching, and we know of nothing that will so much assist in their rational enjoyment as the adoption of some study in natural science. Botany, entomology, ornithology, geology, are all health-affording, nature-loving pursuits. We have passed some of the very happiest moments of our lives in solitary quarries, or on green hill-sides,

"The world forgetting, by the world forgot!"

There, amid the wreck of former creations, and with the glory of the present one around us, we have yielded to the delicious sense of reverie, such as can only be begotten under such circumstances. The shady side of the quarry has screened us from solar heat, and, whilst the air has been melodious with a thousand voices, we have made personal acquaintance with the numerous objects of God's creation, animals and plants. How apt are the thoughts of the poet Crabbe, and how well do they convey the feeling of the young geologist in such places:

"It is a lonely place, and at the side

Rises a mountain rock in rugged pride;

And in that rock are shapes of shells, and forms

Of creatures in old worlds, and nameless worms;

Whole generations lived and died, ere man,

A worm of other class, to crawl began."

II.

BONES.

By Edward Fentone Elwin, Caius College.

Why is it that the students of Osteology are so few in number? It is a branch of science which offers a wide field for original research, and one in which at every step one's interest must get more and more engrossed. It is a branch of science in which a sufficient portion of its elements may be rapidly learned, in order to set the student fairly on his road. The barriers which surround it are few: that is to say, the technical barriers are few. Many people who want to occupy themselves with scientific study are deterred, because of the feeling that there are so many laborious preliminaries to be gone through before they can begin to take any real pleasure in the pursuit. Now, in Osteology it is true that a wide and really almost unexplored field lies open before one, but the equipments necessary to fit one for one's journey are easily attained. The first step is to get thoroughly acquainted with some one typical specimen, as a standard of comparison for all future work. It matters little what species is taken; whichever comes most convenient. Some familiar mammal of fair size is the best. The dog is as good as any, and easy to obtain. There ought never to be any real difficulty in getting a suitable specimen. If expense is no object, the simplest way is to get a preparation, set up so as readily to take to pieces, at any of the bone-preservers' shops in London. One like this costs only a moderate sum, and is, of course, the least trouble, although the manner in which professionals prepare their bones is not altogether satisfactory. But we may regard this as something in the light of a luxury; and it is not hard to prepare one's own specimens, provided we do not mind a little manipulation with unsavoury objects. I have given hints as to the best method by which this may be done in various pages of 'Science-Gossip.'[A] Of course, as one's work gets on, one needs further specimens, but I do not think that anyone who keeps his eyes open need be at a loss in this matter. I have picked up several admirable bones ready cleaned by the wind and weather, and many slightly damaged ones may be got at naturalists' shops for small sums, which are almost as good as the perfect ones for an observer's purposes. Even single and isolated bones are often very instructive.

[A] 'Science-Gossip' for 1873, p. 39; for 1874, p. 226.

But the first main point is that of getting the forms, peculiarities, names, and positions of the bones of one skeleton fully impressed on the student's mind. As to the books which are to help him to do this, it is very hard to know what to recommend. As far as I know, there is no really luminous book on osteology in existence. So far as learning the names and peculiarities of the bones, nothing could be better or more to the purpose than Flower's 'Osteology of the Mammalia'; but this treats only of one class, and does not get beyond technical description. The first and second volumes of Owen's 'Comparative Anatomy of Vertebrates' fill the gap the best of any, and yet these are by no means what we really want. There is a good deal about bones in Huxley's 'Anatomy of Vertebrated Animals,' but in such a fragmentary and scattered form as to be of little use. The fact is, the field is yet open for an Osteological Manual. Much has been written on the subject. Pages of precise and accurate description, beautiful and artistic sheets of plates of bones without number, can be seen in any scientific library. But this is only half the matter. We want to advance a step farther. It is the relation between structure and function which needs working out.

When a new bone finds its way into the student's hands, he observes some peculiarity in shape or structure in which it differs from the bones he is already acquainted with; the question naturally occurs to him, Why does this bone assume one shape in one animal, and in another is modified into a different form? He may look in vain in his books for an answer to his query. And yet it is points like these which, in my opinion, make up the true science of Osteology. It is through careful, constant, and intelligent observation, that these enigmas are to be solved. Observation, indoors and out; close attention to the habits of the animal in question, on the one hand, and careful consideration of its anatomical peculiarities, on the other.

Let me give an instance of this, first of all taking it as an axiom that everything has been done with a purpose. Take, then, the skull of a crocodile. What do we find? The orbits of the eyes, the nasal orifice, the passages leading to the auditory apparatus, all situated on a plane, along the upper flattened surface of the head. What, then, is the cause of this? Palpably to allow the crocodile to remain submerged in the water, with its nose, eyes, and ears just above the surface to warn him of the approach of enemies or prey, and the rest of his carcase securely hidden beneath the waters.

Take another instance. Observe the habits of a mole. With what rapidity it burrows underground, shovelling away the earth with its fore feet. Then look at its skeleton. We find just what we should have expected. The bones of its fore legs of astounding strength and breadth, furnished with deep grooves, which, together with its sternum or breastbone, which is furnished with a keel almost like that of the sternum of a bird, afford attachment to the powerful muscles. Its hind legs, being simply needed for locomotion, are of the normal size. So, also, with the birds. The size of the keel of the sternum varies in proportion to the powers of flight which each species requires, for it is to the broad surfaces of the sternum that the great wing-muscles are attached. Take the skeleton of a hummingbird, which spends its life almost upon the wing. We find there a keel of so vast a size, that the remainder of the skeleton is reduced to insignificance in comparison. Of course, these instances that I have given are all of the most obvious nature, but they serve to show my meaning; and the same line of reasoning can, I am sure, be extended to all the more minute points in osteological structure.

In these researches, one is soon struck by the fact that in the modifications in various bones, or sets of bones, in accordance with the habits of each animal, the original type is never departed from, only modified. See, for example, the paddle of a whale. More like the fin of a fish in general appearance, and yet the same set of bones which are found in the arm of a man, are again found in an adapted form in the paddle of the whale. So, also, the fore leg of a horse preserves the same general plan. What is generally called its knee is in reality its wrist. It is there that we find the little group of bones which forms the carpus. All below it answers to our hand—a hand consisting of one finger.

Take even a wider instance. Compare the arm of a man and the wing of a bird. Still greater adaptations have taken place, and yet the plan remains the same. We still find the clavicle or collar-bone, the scapula or shoulder-blade, the humerus, ulna, and radius, answering to the same bones of our arm, a small carpus or wrist, and finally the phalanges or fingers, simplified and lengthened and anchylosed to form but one series of bone, with the exception of a rudimentary thumb. It is not uncommon to find a rudimentary bone like this which in some allied species is fully developed. The leg of the horse again gives us a very striking example of this. There is, so to speak, only a single finger, but we find, one on each side of this single finger, two small bones, commonly known only as splint-bones. These are the rudimentary traces of the same finger-bones, which in the rhinoceros are fully developed.

Now Osteology abounds in wonderful forms of structure like these. It is a study pregnant with pleasurable results, and is a real profitable study, and one in which each fresh student may do real solid work. It is all the little facts observed by naturalists from time to time all over the world, which on being collected together form the nucleus of knowledge; for indeed all the scientific knowledge which we possess is little more than a nucleus, with which we are supplied. The mere collector of curious objects in no way furthers science. Plenty of people have amassed beautiful collections of insects interesting in their way, but of very transient interest if it goes no farther. The collector possibly knows nothing at all of the wonderful internal structure of the animals he preserves. His insects are to him simply a mosaic—a collection of pretty works of art. So also the shell-collector—for I cannot call such a one as I describe a conchologist—has often, I believe, the most vague ideas of what kind of animals they were that dwelt in the cases he so carefully treasures, and his collection is consequently of a dubious worth to him. Now, to those who study the anatomy of the mollusc as well as its shell, such a collection is full of the deepest interest. He has learnt from his dissections that the habits of every variety of mollusc are accompanied by a variety of structure, which occasions a variety in the shape of the case which envelopes it. It all blends together, and forms a harmonious whole. With a real love for science, as doubtless some of these collectors have, one is sorry to see so much time and money wasted on a pursuit which in their hands yields no fruit of any worth. The work of the mere collector can only be classed with that of the compiler of a stamp-album. Whereas, collections of natural objects, combined with intelligent study, are invaluable and almost indispensable to the naturalist.

In Mr. Chivers's note on Preserving Animals, No. 117 of 'Science-Gossip,' the following passage occurs:—"The skeleton must be put in an airy place to dry, but not in the sun or near the fire, as that will turn the bones a bad colour." I cannot comprehend how this idea should have arisen. Perhaps the most indispensable assistant to the skeleton preparer is that very sun which Mr. Chivers warns him against. The bleaching power of the rays of a hot summer sun is astounding, and bones of the most inferior colour can rapidly be turned to a beautiful white by this means. It is for want of time and care in following out this method that the professional skeleton preparers in London resort to the aid of lime, which, although it makes them white, is terribly detrimental to the bones themselves. In a smoky city like London, the principle of sun-bleaching would be hard to follow; but so great is its value, that more than once I have had valuable specimens sent down to me in the country, by a comparative anatomist in London, to undergo a course of sun-bleaching; and a specimen which I have received stained and blotched, I have returned of a beautiful uniform white, a change entirely due to that sun which we are told to beware of.

The question, How are skeletons to be prepared? is one which is repeatedly asked. People desire a method by which with little trouble the flesh may be removed from a specimen, and a beautiful skeleton of ivory whiteness left standing in its natural position. I can assure all such inquirers that this cannot be accomplished by any method at all. The art of preparing bones is a long, elaborate, and difficult one, and he who wishes to become a proficient in it must be alike regardless to the most unpleasant odours, and to handling the most repulsive objects. Mr. Chivers's receipt for the maceration of specimens is about the best which one could have, only I should not advise so frequent a change of the water. What is needed is as rapid a decomposition of the flesh as is possible, and then the cleaning of the skeleton just before the harder ligaments have also dissolved. But this requires very careful watching, and with the utmost pains it is almost impossible to get a skeleton entirely connected by its own ligaments.

Another point which must be taken into consideration is this: What use is to be made of the specimens after they are prepared? Are they for purposes of real study, or simply as curious objects to look at? If the latter is the purpose, I must confess I do not think they are worth the trouble of preparing. If the former is the object for which they are intended, then I think no care or pains are thrown away. But for the real student of Osteology the separated bones, as a rule, are far more valuable than those which are connected. He needs one or two set up for purposes of reference, but the great bulk of his specimens should be separate bones. Osteology is one of the most delightful branches of comparative anatomy, and one not very hard to master. Let anyone try the experiment by getting together a few bones—and those from the rabbit or the partridge we have had for dinner are by no means to be despised—and then, by purchasing Flower's 'Osteology of the Mammalia,' which is a cheap and first-rate book, he will learn what the study of the skeleton really is. And then let him be on the look-out for specimens of all kinds on all occasions, bringing home all suitable objects he meets with in his walks, however unsavoury they may be, and he will be astonished to find how many specimens he will get together in the course of a year. I have now myself upwards of seventy skulls of various kinds, with often the rest of the skeleton as well, the greater part of which were gradually collected, by keeping constantly on the watch for them, within a year and a half.

III.

BIRDS' EGGS.

By Thomas Southwell, F.Z.S., etc.

I can imagine no branch of natural history more fascinating in its nature, or more calculated to attract the attention of the young, than the study of the nests and eggs of birds; the beauty of the structure of the one, and of the form and colour of the others, cannot fail to excite wonder and admiration; and the interest thus excited, if rightly directed, may, and indeed has, in many instances, led to the development of that passionate love for all nature's works, that careful and patient spirit of investigation, and that deep love for truth which should all be characteristics of the true naturalist. Who can look back upon the days, perhaps long passed away, when as a school-boy he wandered through the woods and fields, almost every step unfolding to him some new wonder, some fresh beauty—glimpses of a world of wonders only waiting to be explored—who can look back to such a time without feeling that in those wanderings there dawned upon his mind a source of happiness which in its purity and intensity ranks high amongst those earthly pleasures we are permitted to enjoy, and which has influenced him for good in all the changes which have since come upon him, lightening the captivity of the sick room, and adding fresh brightness to the enjoyments of health.

Between the true naturalist and the mere "collector" there is a wide gap, and I trust that none for whom I am writing will allow themselves to drift into the latter class; the incalculable mischief wrought by those who assist in the extermination of rare and local species by buying up every egg of a certain species which can be obtained, for the mere purpose of exchange, cannot be too much deprecated, and I hope that none of my readers will be so guilty; to them the pleasures of watching the nesting habits of the bird, the diligent search and the successful find are unknown; the eggs in such a cabinet are mere egg-shells, and not objects pregnant with interest, recalling many a happy ramble, and many a hardly-earned reward in the discovery of facts and habits before unknown. Every naturalist must be more or less a collector, but the naturalist should always be careful of drifting into the collector, his note-book and his telescope should be his constant and harmless companions.

When the writer first commenced his collection, the mode of preparing the specimens for the cabinet was very rude indeed, and the method of arranging equally bad; he is sorry to say the popular books upon the subject which he has seen do not present any very great improvement; in giving the results of his own experience, and the plan pursued by the most distinguished oologists of the day, who have kindly allowed him to explain the methods they adopt, he will, he trusts, save not only much useless labour, but many valuable specimens.

Before saying a word as to preparing specimens for the cabinet, I wish to impress upon the young oologist the absolute necessity for using the greatest care and diligence in order satisfactorily to identify, beyond possibility of doubt, every specimen, before he admits it to his collection. Without such precautions, what might otherwise be a valuable collection is absolutely worthless; and it is better to have a small collection of authentic specimens than a much larger one, the history of which is not perfectly satisfactory; in fact, it is a good rule to banish from the cabinet every egg which is open to the slightest doubt. There are some eggs which, when mixed, the most experienced oologist will find it impossible to separate with certainty, and which cannot be identified when once they are removed from the nest.

The difficulties in the way of authentication are by no means slight, but space will not allow me to dwell upon them; the most ready means, however, is that of watching the old bird to the nest, although even in this, as the collector will find by experience, there is a certain liability to error. In collecting abroad it will be found absolutely necessary (however reluctant we may be to sacrifice life) to procure one of the parents with the nest and eggs. As we are writing for beginners at home, we trust such a measure will rarely be necessary; but that an accurate knowledge of the appearance of the bird, its nesting habits, the situation, and the materials of which the nest is composed, will be found amply sufficient to identify the eggs of our familiar birds. This knowledge of course is only to be obtained by patient and long observation; but it is just by such means that the student obtains the practical insight into the habits and peculiarities of the objects of his study, together with the careful and exact method of recording his observations, which eventually enables him to take his place amongst the more severely scientific naturalists whom he desires to emulate.

I will first describe the tools required, and then proceed to the mode of using them.