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NOTICES TO CORRESPONDENTS.

ALL communications relative to advertisements, post-office

orders, and orders for the supply of this Joumal should be addressed to the PUBLISHER. All contributions, books, and pamphlets for the EDITOR should be sent to 192, Piccadilly, London, W. To avoid disappointment, contri. butions should not be received later than the 15th of each month. No notice whatever can be taken of communi. cations which do not contain the name and address of the writer, not necessarily for publication, if desired to be withheld. We do not undertake to answer any queries not specially connected with Natural History, in accordance with our acceptance of that term ; nor can we answer queries which might be solved by the correspondent by an appeal to any elementary book on the subject. We are always prepared to accept queries of a critical nature, and to publish the replies, provided some of our readers, besides the querist, are likely to be interested in them. We cannot undertake to return rejected manuscripts unless sufficient stamps are enclosed to cover the return postage. Neither can we promise to refer to or return any manuscript after one month from the date of its receipt. All microscopical drawings intended for publication should have annexed thereto the powers employed, or the extent of enlargement, indicated in diameters (thus : X 320 diameters). Communications intended for publication should be written on one side of the paper only, and all scientific names, and names of places and individuals should be as legible as possible. Wherever scientific names or technicalities are employed, it is hoped that the common names will accompany them. Lists or tables are inad. missible under any circumstances. Those of the popular names of British plants and animals are retained and regis. tered for publication when sufficienlty complete for that purpose, in whatever form may then be decided upon. ADDRESS No. 192, PICCADULY, LONDON, W.

P. P.-Gardiner, High Holborn, or Cooke, Oxford Street, London. We do not know where Bermuda earth can be obtained.

M. R.-" Harvey's Synopsis of British Seaweeds : " Reeve & Co.; 58. You may obtain" prepared skins" of either of the naturalists above-named (answer to P. P.).

S. G.--The best is Val Disneria spiralis.

S. A. M.-It is such a common occurrence that we cannot afford it space.

S. M. P.--We object to giving very precise localities for rare plants, which may end in their extermination. There is war enough against rare plants and apimals now, which we have no desire to increase. We would not, if we could, give the Dorsetshire station, and must be excused from inquiring.

E. G. M.-One of the curious Algæ, probably from the Southern Ocean, of the genus Corallina.

E. T. 8.-The hard fungus is Sclerotium durum, with a mould (Polyactis cinerea) growing from it.

W. F. H.-Closterium, in such a miserable condition that no one would thank you for them.

D. C. B.-Obtain • Gardner's Taxidermy” for one shilling or eighteenpence.

R.G.-Apparently Podura (Achorutes) fimetaria.- 1. 0. W.

EXCHANGES. BIRDS' Ecos (British) for British Lepidoptera.-Apply to H. L., Rose-hill, Old Trafford, Manchester

CHINESE BEETLES, &c. for injections or entomological slide.-W.T. Loy, 10, Rood.lane, Eastcheap.

BRITISH MOSSES.-West country mosses offered in ex. change for Devonshire or other species.-F. B., 19, Clarendon. place, Plymouth.

FORAMINIFERA from Kentish chalk for other good objects (mounted).-W. Freeman, 2, Ravensbourne-hill, Lewishamroad, Greenwich, S.E.

ORAN EARTH and seeds of Paulownia.-J. W. Leakey, 3. Prince of Wales Avenue, Malden-road, Haverstock-bill.

MUMMY CLOTH (genuine from Luxor), unmounted, for sections, animal or vegetable.-W. Spicer, Itchen Abbas, Alresford.

HAIR OF Tiger, Leopard, &c., and corallines, for mounted palates of mollusca, except whelk and periwinkle.-E. C. Jellie, Eldon Villa, Redland, Bristol,

EPITHEMIA TURGIDA or Coscinodiscus (mounted) for Arach. noidiscus or Triceratium.-G. Moore, Dereham-road, Norwich.

FERNS.-Seedling Gymnogramma Chaerophylla for seedling G.leptophylla.-H. J. Charlton, 2, Richmond-grove, Queen'sroad, Everton, Liverpool.

SMUT IN WHEAT.-Send stamped envelope (with address) to J. J. Fox, Devizes.

Fisi SCALES offered for unmounted specimens of the same.-J.H.M., 17, Walham-grove, St. John's, Fulham, S.W.

LAND AND FRESHWATER SHELLS (British) wanted in exchange for land and freshwater shells of Maine (U.S.). Address, Rev. E.C. Bolles, Portland, Maine, U. States.

FIBROUS COPPER offered for other mineral objects (un. mounted).-A.S., 2, Hanover-place, Rye-lane, Peckham.

MICROSCOPIC OBJECts for bat hairs from named specimens. -Geo, Potter, Montpellier-road, Upper Holloway, N.

A. R. W.-“Nichols's Dictionary of Scientific Terms” will perhaps suit you; price 12s. Reeve & Co.

M. H.-The hairs on your larvæ are simple, not compound, as in Anthrenus.

A. K. L. -Because heat and spirit will dissolve some crystals, either, or both, often accompany mounting in balsam.

J. A., Jun.-The Natural History division of the “English Cyclopædia " now publishing in parts or volumes by Bradbury & Evans.

G. W.-A good suggestion, and will be remembered.

J. C.-"Microscopic Fungi,” 6s.; “ British Fungi," 6s. Published by R. Hardwicke, 192, Piccadilly. To preserve fungi, consult these works.

M. G. F. asks the name of the “phosphorescent centi. pede.” The “Apples of Sodom” are galls formed on a species of oak.

A. B.-Jf communications are not inserted within three or four months, it may reasonably be concluded that we have been unable to find room for them.

LIZZIE.-See Notes and Queries in this present number for a full reply, headed “Squirrels."

J. W. w.-We have no knowledge of the method employed by Dr. Gregory with Glenshira sand.

A.E. M.-Only by continued practice and perseverance can you hope to equal the slides of selected Diatoms you name, Is it worth the labour?

T. J.-The fly is Bibio Marci, so named because it appears in abundance at the period of St. Mark's Day. The other insect is a Pimpla, family Ichneumonidæ, too much broken for determination.-F.W.

J. R., JUN.-Several kinds of Willow Galls, so that the query is vague. The covers will also hold the advertise ments.

A. P.--The Waxwing has visited a great many localities this year. It is much to be regretted that they are so ruthlessly destroyed.

T.'J.-There has been a parasitic fungus on No. 3, but it is all gone. It is old and exolete.

J. H. D.-See our answer to G. F. P. in January number, p. 24.

W. W. S.-It is Torula herbarum, spores globose, in chains

S. L. B.-We do not hear of any maker of the section machine you name. A machine called "Topping's Machine" may be had for 15s.

J. M.-No. 1. Cyprea pediculus (L.); 2. Oliva bullata (Reeve); 3. Conus (Sp.); 4. Lucina divaricata (L.); 5. Neritina viridis (L.); 6. Pecten vestalis (Reeve); 7. Cardium (Sp.).—R. T.

Mosses (J. F.).-1. Weissia controversa; 2. Pleuridium alternifolium ; 3. Trichostomum rigidulum ; 4. Hedwigia ciliata; 5. Didymodon rubellus.-R. B.

J.H.-There is nothing strange in any of the Reptilia byber. nating.

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ERALATALARE

HOW TO STUDY NATURAL HISTORY.*

BY PROFESSOR HUXLEY, F.R.S., &c.

[graphic]

ATURAL HISTORY is the advance of knowledge has gradually widened the name familiarly applied to the distance between mineralogy and its old associates, study of the properties of such while it has drawn zoology and botany closer tonatural bodies as minerals, plants, gether; so that of late years it has been found and animals; the sciences which convenient and indeed necessary) to associate

embody the knowledge man has the sciences which deal with vitality and all its o acquired upon these subjects phenomena under the common head of “biology;"

are commonly termed Natural and the biologists have come to repudiate any
Sciences, in contradistinction to blood-relationship with their foster-brothers, the
other so-called "physical,"sciences; mineralogists.
and those who devote themselves Certain broad laws have a general application

especially to the pursuit of such throughout both the animal and the vegetable L o sciences have been, and are, commonly worlds ; but the ground common to these kingdoms 06 termed“ Naturalists."

of nature is not of very wide extent, and the multi. Linnæus was a naturalist in this wide plicity of details is so great, that the student of

sense, and his “Systema Naturæ" was living beings finds himself obliged to devote his 76 a work upon natural history in the attention exclusively either to the one or the other, 1

broadest acceptation of the term ; in it | If he elects to study plants, under any aspect, we

that great methodizing spirit embodied all know at once what to call him; he is a botanist, that was known in his time of the distinctive and his science is botany. But if the investigation characters of minerals, animals, and plants. But the of animal life be bis choice, the name generally enormous stimulus which Linnæus gave to the in. applied to him will vary, according to the kind of vestigation of nature soon rendered it impossible animals he studies, or the particular phenomena of that any one man should write another “Systema animal life to which he confines his attention. If Naturæ,” and extremely difficult for any one to | the study of man is his object, he is called an become a naturalist such as Linnæus was.

anatomist, or a physiologist, or an ethnologist; but Great as have been the advances made by all the if he dissects animals, or examines into the mode in three branches of science, of old included under the which their functions are performed, he is a comtitle of natural history, there can be no doubt that parative anatomist or comparative physiologist. If zoology and botany have grown in an enormously be turns his attention to fossil animals, he is a palægreater ratio than mineralogy; and hence, as I sup- ontologist. If his mind is more particularly directed pose, the name of "natural history” bas gradually to the description, specific discrimination, classificabecome more and more definitely attached to these | tion, and distribution of animals, he is termed a prominent divisions of the subject, and by "natu zoologist. ralist” people have meant more and more distinctly For my present purpose, however, I shall recogto imply a student of the structure and functions of | nize none of these titles save the last, which I shall living beings.

employ as the equivalent of botanist; and I shall However this may be, it is certain that the use the term zoology as denoting the whole doctrine

of animal life, in contradistinction from botany,

which signifies the whole doctrine of vegetable * The substance of these remarks was embodied in a lecture on Zoology delivered at the South Kensington

life. Museum in 1860.

| Employed in this sense, zoology, like botany, is No. 28.

E

divisible into three great but subordinate sciences, the same as in the other divisions; but the appen. morphology, physiology, and distribution, each of dages look at first as if they were very different; which may, to a very great extent, be studied inde and yet when we regard them closely, what do we pendently of the other.

find? A stalk and two terminal divisions exactly Zoological morphology is the doctrine of animal as in the others, but the stalk is very short and form or structure. Anatomy is one of its branches, very thick, the terminal divisions are very broad development is another; while classification is the and flat, and one of them is divided into two expression of the relations which different animals

pieces. bear to one another, in respect of their anatomy and I may say, therefore, that the sixth segment is their development.

like the others in plan, but that it is modified in its Zoological distribution is the study of animals in details. relation to the terrestrial conditions which obtain The first segment is like the others, so far as its now, or have obtained at any previous epoch of the ring is concerned; and though its appendages differ earth's history.

from any of those yet examined in the simplicity of Zoological physiology, lastly, is the doctrine of their structure, parts corresponding with the stem the functions or actions of animals. It regards and one of the divisions of the appendages of the animal bodies as machines impelled by certain other segments can be readily discerned in them. forces, and performing an amount of work, which Thus it appears that the lobster's tail is composed can be expressed in terms of the ordinary forces of of a series of segments which are fundamentally nature. The final object of physiology is to deduce similar, though each presents peculiar modifications the facts of morphology on the one hand, and those of the plan common to all. But when I turn to the of distribution on the other, from the laws of the fore part of the body, I see at first nothing but a molecular forces of matter.

great shield-like shell, called technically the “caraSuch is the scope of zoology. But if I were to pace," ending in front in a sharp spine, on either content myself with the enunciation of these dry side of which are the curious compound eyes, set definitions, I should ill exemplify that method of upon the ends of stout moveable stalks. Behind studying this branch of physical science, which it is these, on the under side of the body, are two pairs my chief business to recommend. Let us turn of long feelers or antennæ, followed by six pairs of away, then, from abstract definitions. Let us take jaws, folded against one another over the mouth, some concrete living thing, some animal (the and five pairs of legs, the foremost of these being commoner the better), and let us see how the appli- | the great pinchers or claws of the lobster. cation of common sense and common logic to the | It looks at first a little hopeless to attempt to obvious facts it presents inevitably leads us into all find in this complex mass a series of rings, each these branches of zoological science.

with its pair of appendages, such as I have shown I will suppose that I have before me a lobster. you in the abdomen, and yet it is not difficult to When I examine it, what appears to be the most demonstrate their existence. Strip off the legs, and striking character it presents ? Why, I observe you will find that each pair is attached to a very that this part which we call the tail of the lobster definite segment of the under wall of the body; is made up of six distinct hard rings and a seventh but these segments, instead of being the lower terminal piece. If I separate one of the middle parts of free rings, as in the tail, are such parts of rings, say the third, I find it carries upon its under | rings which are all solidly united and bound tosurface a pair of limbs or appendages, each of gether; and the like is true of the jaws, the feelers, which consists of a stalk and two terminal pieces. and the eye-stalks, every pair of which is borne

If I now take the fourth ring I find it has the upon its own special segment. Thus the conclusion same structure, and so have the fifth and the is gradually forced upon us that the body of the second; so that in each of these divisions of the lobster is composed of as many rings as there are tail I find parts which correspond with one another, pairs of appendages, namely, twenty in all, but that a ring and two appendages; and in each appendage the six hindmost rings remain free and moveable, a stalk and two end pieces. These corresponding while the fourteen front rings become firmly solparts are called, in the technical language of dered together, their backs forming one continuous anatomy, “homologous parts.” The ring of the shield—the carapace. third division is the “homologue” of the ring of Unity of plan, diversity in execution, is the lesson the fifth; the appendage of the former is the homo- taught by the study of the rings of the body; and logue of the appendage of the latter. And as each | the same instruction is given still more emphatically division exhibits corresponding parts in correspond- by the appendages. If I examine the outermost ing places, we say that all the divisions are con- jaw, I find it consists of three distinct portions-an structed upon the same plan. But now let us inner, a middle, and an outer, mounted upon a consider the sixth division. It is similar to, and yet common stem; and if I compare tihs jaw with the different from, the others. The ring is essentially legs bebind it or the jaws in front of it, I find it quite easy to see that in the legs it is the part of each of the rings thus sketched out, a pair of budthe appendage which corresponds with the inner like prominences made their appearance-the rudidivision, which becomes modified into what we ments of the appendages of the ring. At first all know familiarly as the “leg,” while the middle the appendages were alike, but as they grew, most division disappears, and the outer division is hidden of them became distinguished with a stem and two under the carapace. Nor is it more difficult to dis- terminal divisions, to which in the middle part of cern that, in the appendages of the tail, the middle the body was added a third outer division; and it division appears again, and the outer vanishes; was only at a later period that, by the modification while on the other hand, in the foremost jaw, the or abortion of certain of these primitive constiso-called mandible, the inner division only is left; tuents, the limbs acquired their perfect form. and, in the same way, the parts of the feelers and Thus the study of development proves that the of the eye-stalks can be identified with those of the doctrine of unity of plan is not merely a fancy ; legs and jaws.

that it is not merely one way of looking at the But whither does all this tend? To the very matter, but that it is the expression of deep-seated remarkable conclusion that a unity of plan, of the natural facts. The legs and jaws of the lobster same kind as that discoverable in the tail or abdo may not merely be regarded as modifications of a men of the lobster, pervades the whole organization common type,-in fact and in nature they are so,of its skeleton, so that I can return to any one of the leg and the jaw of the young animal being, at the rings of the tail, and by adding a third division first, indistinguishable.

plan of any ring of the body. I can give names to the zoologist finds them to be of universal applicaall the parts, and then if I take any segment of the tion. The investigation of a polype, of a snail, of body of the lobster, I can point out exactly what a fish, of a horse, or of a man, would have led us, modification the general plan has undergone in that though by a less easy path, perhaps, to exactly the particular segment; what part has remained move- | same point. Unity of plan everywhere lies hidden able, and what has become fixed to another; what | under the mask of diversity of structure—the comhas been excessively developed and metamorphosed, plex is everywhere evolved out of the simple. and what has been suppressed.

Every animal has at first the form of an egg, and But I imagine I hear the question, how is all this every animal and every organic part, in reaching its to be tested? No doubt it is a pretty and ingenious adult state, passes through conditions common to way of looking at the structure of any animal, but other animals and other adult parts; and this leads is it anything more? Does Nature acknowledge in me to another point. I have bitherto spoken as if any deeper way this unity of plan we seem to the lobster were alone in the world, but, as I need trace ?

hardly remind you, there are myriads of other The objection suggested by these questions is a animal organisms. Of these, some-such as men, very valid and important one, and morphology was horses, birds, fishes, snails, slugs, oysters, corals, in an unsound state so long as it rested upon the and sponges-are not in the least like the lobster. mere perception of the analogies which obtain But other animals, though they may differ a good between fully formed parts. The unchecked inge deal from the lobster, are yet either very like it, or nuity of speculative anatomists proved itself fully are like something that is like it. The cray fish, competent to spin any number of contradictory the rock lobster, and the prawn, and the shrimp, for hypotheses out of the same facts, and endless mor example, however different, are yet so like lobsters, phological dreams threatened to supplant scientific that a child would group them as of the lobster theory.

kind, in contradistinction to snails and slugs; and Happily, however, there is a criterion of morpho. these last again would form a kind by themselves, logical truth, and a sure test of all homologies. in contradistinction to cows, horses, and sheep, the Our lobster has not always been what we see it; it cattle kind. was once an egg, a semifluid mass of yolk, not so But this spontaneous grouping into “kinds” is big as a pin's head, contained in a transparent the first essay of the human mind at classification, membrane, and exhibiting not the least trace of any or the calling by a common name of those things one of those organs whose multiplicity and com- that are alike, and the arranging them in such a plexity, in the adult, are so surprising. After a manner as best to suggest the sum of their likenesses time a delicate patch of cellular membrane appeared | and unlikenesses to other things. upon one face of this yolk, and that patch was the | Those kinds which include no other subdivisions foundation of the whole creature, the clay out of than the sexes, or various breeds, are called, in which it would be moulded. Gradually investing technical language, species. The English lobster is the yolk, it became subdivided by transverse con- a species, our cray fish is another, our prawn is strictions into segments, the forerunners of the another. In other countries, however, there are rings of the body. Upon the ventral surface of lobsters, cray fish, and prawns very like ours, and yet presenting sufficient differences to deserve dis- | trary, in their earliest condition they are all alike, tinction. Naturalists, therefore, express this re- and the primordial germs of a man, a dog, a bird, semblance and this diversity by grouping them as a fish, a beetle, a snail, and a polype, are in no distinct species of the same "genus.” But the essential structural respects, distinguishable. lobster and the cray fish, though belonging to distinct In this broad sense, it may with truth be said, genera, have many features in common, and hence that all living animals, and all those dead creations are grouped together in an assemblage which is which geology reveals, are bound together by an called a family. More distant resemblances connect | all-pervading unity of organization, of the same the lobster with the prawn and the crab, which are character, though not equal in degree, to that which expressed by putting all these into the same order. enables us to discern one and the same plan amidst Again, more remote, but still very definite, resem the twenty different segments of a lobster's body. blances unite the lobster with the woodlouse, the Truly it has been said, that to a clear eye the smallest king crab, the water-flea, and the barnacle, and fact is a window through which the Infinite may be separate them from all other animals; whence they seen. collectively constitute the larger group, or class, Turning from these purely morphological conCrustacea. But the Crustacea exhibit many peculiar siderations, let us now examine into the manner in features in common with insects, spiders and centi. which the attentive study of the lobster impels us pedes, so that these are grouped into the still larger into other lines of research. assemblage or "province" Articulata, and, finally, Lobsters are found in all the European seas; but the relations which these have to worms and other | on the opposite shores of the Atlantic and in the lower animals, are expressed by combining the seas of the southern hemisphere they do not exist. whole vast aggregate into the sub-kingdom of | They are, however, represented in these regions by Annulosa.

very closely allied, but distinct forms—the Homarus If I had worked my way from a sponge instead of Americanus and the Homarus Capensis, so that we a lobster, I should have found it associated, by like may say that the European has one species of ties, with a great number of other animlas into the Homarus ; the American, another ; the African, subkingdom Protozoa ; if I had selected a fresh- / another; and thus the remarkable facts of geowater polype or a coral, the members of what graphical distribution begin to dawn upon us. naturalists term the subkingdom Cælenterata, would Again, if we examine the contents of the earth's Lare grouped themselves around my type; had a crust, we shall find in the later of those deposits, snail been chosen, the inhabitants of all univalve which have served as the great burying grounds of and bivalve, land and water shells, the lamp shells, past ages, numberless lobster-like animals, but none the squids, and the sea mat would have gradually so similar to our living lobster as to make zoologists linked themselves on to it as members of the same sure that they belonged even to the same genus. subkingdom of Mollusca ; and finally, starting from If we go still further back in time, we discover in man, I should have been compelled to admit first, the oldest rocks of all, the remains of animals, conthe ape, the rat, the horse, the dog, into the same structed on the same general plan as the lobster, class, and then the bird, the crocodile, the turtle, and belonging to the same great group of Crustacea; the frog, and the fish, into the same subkingdom of but for the most part totally different from the Vertebrata.

lobster, and, indeed, from any other living form of And if I had followed out all these various lines crustacean ; and thus we gain a notion of that sucof classification fully, I should discover in the end cessive change of the animal population of the that there was no animal, either recent or fossil, globe, in past ages, which is the most striking fact which did not at once fall into one or other of these revealed by geology. subkingdoms. In other words, every animal is Consider, now, where our inquiries have led us. organized upon one or other of the five, or more, We studied our type morphologically, when we plans, whose existence renders our classification determined its anatomy and its development, and possible. And so definitely and precisely marked is when comparing it, in these respects, with other the structure of each animal, that, in the present | animals, we made out its place in a system of classistate of our knowledge, there is not the least fication. If we were to examine every animal in a evidence to prove that a form, in the slighest degree similar manner we should establish a complete body transitional between any two of the groups Verte. of zoological morphology. brata, Annulosa, Mollusca, and Calenterata, either Again, we investigated the distribution of our exists, or has existed, during tbat period of the type in space and in time, and, if the like had been earth's history which is recorded by the geologist. done with every animal, the sciences of geographical Nevertheless, you must not for a moment suppose, and geological distribution would have attained their because no such transitional forms are known, that limit. the members of the subkingdoms are disconnected But observe one remarkable circumstance, that, from, or independent of, one another. On the con- | up to this point, the question of the life of these

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