Part 24 (1/2)

Was I not justified in asserting that the unity of the aniestive tube? and that this is the unchanging basis upon which the Creator of the animal world had raised his varied constructions?

Hoould it be, then, if ere to take the insect fro-point when it is only a worestive tube? for I a you a small portion of its history here; a history you must knohich reveals a miracle still more wonderful than the transfor! There is a brilliant-colored fly which co about the meat-safe--the bluebottle--do you know her? It is on her account that we put large covers of iron wire over the dishes of meat; but, perhaps, you never troubled yourself to think why

But the truth is, she only coood roast-h to do so, you would soon afterwards see it swar with little white worms, which would entirely take away all your appetite These wors by-and-by if you only give the-table, I assure you they deserve more interest than you may think When we come to speak of worms, ill ask of them to let out the secret of the mysterious transformations of animals

In theon the _perfect insect_, as this little creature is called when he has passed through the interes which separate hiiveto you as if you were a grown-up wos of this sort in any other way And now that you have been introduced into the ht to faested to reat would be irl! And I flatter myself that I have so far set your brain, to work, under pretence of aether unfounded I found it necessary to say this to you in confidence, because I have just read over our first conversations, and perceive that I have insensibly put you on a different diet froed to corown older since, and that you are now acquainted with a great s which you had never heard spoken of then And this is the secret of all transforround that was quite unknown to us; but as ent along, our wings row, and we are now able to fly a little!

Do not be afraid, however; I will exercise your tiny butterfly-wings very carefully just at present We have only to examine what becomes of the _chyle_ of the cockchafer after it has been prepared in the pretty little tube so finely wrought We men have _chyliferous_ vessels which draw up chyle from the intestines and throithin a short distance of the heart, into the torrent of blood, where its education is completed But the cockchafer, who has no other vessels than his air-pipes, and the _dorsal tube_, which has no communication with the intestines, what is he to do? Do not distress yourself about hiether, and fill it ater Sew it together as firmly as you may on all sides, the water will have no difficulty in escaping through the meshes And this is just what happens with the little tubes found in animals, the coats of which are formed of interwoven fibres By-the-by, from thence comes their name of ”_tissue_,” which they share in common with all the solid substances of the body, for all were once supposed to have the saeneral structure

The intestine of the cockchafer floats, did I not say? in the lake of blood which fills the whole cavity of the body Well, then, the chyle has only to penetrate through these coats, to go where it is wanted

Hence it is not at all surprising that this blood should be white; and I have very good reasons just now for co directly fro any other process; by which you ans of the cockchafer), though differing in appearance so entirely from our own, is reducible to the same elements of construction, and that life is maintained by the same process as with us; namely, by the action of the air upon the albumen extracted from food The cockchafer, it is true, isa fellow-creature of ours than even the horse; but the principle of life is the sah to cause children, who can feel and reason, to think twice before they begin to torture, by way of aoodness has subjected to the same conditions as our own I speak this to thoseaniriculturists, who have necessarily to contend with the devourers of their harvests, and whom, I admit, it would not be reasonable to bind down by the maxim of Uncle Toby

[Footnote: I have introducedto do here, in order to make you acquainted with a few lines of Sterne, which I wish I could place before the eyes of every child in the world

”Go!” said he, one day at table, to an enor around his nose and had cruelly tormented hiht him in his hand ”Go! I will not do thee any har the room with the fly in his hand; ”I would not hurt a hair of your head

Go!” said he, opening theand his hand at the sao, poor little devil; aith you; why should I do you any harh to contain both of us!”]

But now to finish with the cockchafer We have got to examine one very important part of his body, that which in other anian our study: I mean the mouth

You know that this is the essentially variable point in the digestive tube; so that you will not be ether new The reat number of small pieces placed externally round the entrance to the _alimentary canal_; but the names of these, as they would not interest you, I will not enter upon with you; more especially as they refer to such tinytheain on the owner Of these pieces only two are worth our attention These are two bits of extremely hard horn, placed one on each side of the animal, which are called ”_mandibles_” and which serve the cockchafer to cut up the leaves which he eats Fancy your share of teeth being two huge things fixed in the two corners of your ainst the other till they meet under the nose! You would then attack your tarts with the weapons of the cockchafer! You would not, however, be able to bite theh from the top to the bottom, as is done by all the animals e have yet seen It is this which so peculiarly distinguishes the insect's ht by the bird and the tortoise, that it is possible to eat with two pieces of horn The cockchafer nos us how to eat sideways; but this is merely an accessory detail It does not affect what happens after the mouthful is sed All insects, however, have not this peculiarity

The cockchafer belongs to the category of grinding insects as they are called, who bite their food: but there is the category of the sucking insects (or suckers), whose food consists of liquids; and these insects are furnished in a different manner

In the innocent butterfly, who lives on the juice of flowers, the digestive tube terminates externally in a sort of _trunk,_ twisted in several convolutions, which is nothing ation of the thich becoether When the insect alights on a flower, he suddenly unrolls this trunk, and sucks in the juices from the depth of its ”corolla,” as you would drink up liquid with a straw from the bottom of a s a butterfly in his labors ast the flowers: sometimes he stops still, but oftener he is contented to hover over them; and, as he does so, you will see a little loose thread, as it were, move backwards and forwards as fast as possible: this is his trunk, which he darts out, while flying, into the corolla of the flowers, but which scarcely seems to touch them, so delicate is its approach

Less inoffensive far is the trunk of the nat, and of all the detestable troop of blood-sucking flies It is always a tube; but this tube is no longer a simple straw, but a sheath furnished with stilettos of such exquisite delicacy and te is comparable to them; and these, as they play up and down, pierce the skin of the victim, like the lancets of the lamprey, and, like thest the _parasites,_ the last and lowest group of insects, the stiletto-sheath is reduced to the size of a kind of little tube-shaped beak, which, when not in use, folds down like the fangs of the rattlesnake

You do not know, perhaps, what a parasite is The word conifies literally, ”_that which moves round the corn_” The Greeks applied it to those shameless paupers who, to escape honest labor, reat, and enjoyed themselves at their expense These parasites are little anie ones, to suck in, without having worked for it, the blood which the others have hts, and tears its victim in pieces; and then, by means of that interior labor which I have spent soliquid: and when all this is acco his hairs, coolly draws out for his own use the valuable blood obtained with so much effort There are many parasites in the world, in with--who are perfectly happy to chew your bread without asking where the corn coh to see plainly that this indifference ought not to last, and that it is not honorable to go on living in this indefinite manner at other people's cost only

You will some day have duties to fulfil, which you should accustom yourself to think of now, in order that you may prepare yourself for them beforehand, so that it h thefro in return, I advise you to conjure up this idea when the ti to be of use The sort of thing is not always very a, I admit, but you must look upon it as the ladder by which you will be enabled to rise froradation of a parasitical life If you were in a well, and soet up by, I do not think you would co it It is for you, then, to consider whether you would like to remain for ever in your present condition; for those who learn nothing, who _sub, but to show off and amuse themselves--these remain parasites all their lives in reality, however little they e, however, there is still no disgrace in the s are allowed to be parasitical; but on this subject I must return to a point in the history of ani of the crocodile, that the perfect state of the inferior animals is found represented in the infancy or less perfect state of those above theard to insects All the young of theanimals: for they all live at first on theirmore than blood in a peculiar state But the naenerally confined to those which take up their abode on the bodies of their hosts; though in conat and his relations, hen once full, make their bow and are off, like the kitten when he has finished sucking Well, withoutto find fault, if we descend to the lower ranks of thethem many parasites in the received sense of the word You remember the pouch to which the aroo re continually all the ti the four following oes in and out, and strolls about betweenones of its class, and is then an ani thus a twofold exareat Creator to repeat Hi for the infancy of the mam the butterfly in the hu-bird, who may fairly be called a vertebrated butterfly, and reproducing the gnat in the vaed and perfected revise of the original pattern, whence cohts

And now, surely, I have said enough about these parasites, whose very name, I suspect, will make you shudder after my impertinent application of it Never et rid of whatever you find hu in the position I have hinted at Do all you can to bring happiness to the parents on whoive their life-blood so willingly for your good God has made you very different frouide them Do not be like them, then, in conduct By a little obedience and love--child as you are--you can pay theain

LETTER xxxVIII

CRUSTACEA--MOLLUSCA (_Crustaceans and Mollusks_)

_Crustaceans_

Crustaceans consist of cray-fish, crabs, lobsters, and prahowhich ht to be placed Like the the same action of the mandibles; and _suckers_, who are also parasites, and have tubular sheaths containing stilettos Mammals and birds are the victims of parasitical insects; fishes have been reserved for the crustaceans, who do not disdain also to fasten upon their hu thereat A few live on land, but an immense majority in water, and seem destined to represent, in the aquatic world, the aerial class of insects, from whom, however, they differ in many ways

The first difference is in that stony crust hich they are enveloped, like the cockchafer in his horny cuirass, and which you h if you have ever eaten lobster Wherever we meet with horn in insects, we find stone in crustaceans The jaws are stony, and the teeth of the stomach also They are constructed on the saestive tube is less coe stomach, instead of that series of stoanisation of birds On the other hand, if a so loosely in the body, as we have just seen it in the cockchafer aenerally so profusely ainst each other, that they fore compact lump--a true liver, to sum up all--from which issues, as from ours, a _choledochian canal_, a bile duct, _i e_, which passes out into the intestine at the entrance of the pylorus

You recollect that canal of the liver which I was afraid to tell you the naly? Well, this is that formidable name!