Omphalos Part 14

With these physiological facts ascertained, let us proceed to the determination of the actual age of our n.o.ble Dauntelah. The molar in present use has a length of about nine inches, and a diameter of three and a half. Its crown is crossed by about eighteen enamel-plates; of which the anterior ones are much worn away, while the hinder ones can scarcely be counted with precision, as they have not wholly cut their way through the gum. These characters indicate the fifth molar (or set of molars) of the whole life-series. And the following facts will help us now to fix the actual age, at least approximately.

The first molar cuts the gum at two weeks old, is in full use at three months, and is shed in the course of the second year. The second cuts the gum at about six months, and is shed in the fifth year. The third appears at two years, is in full use about the fifth year, and finally disappears about the ninth year. In the sixth year the fourth breaks from the gum, and lasts till the animal's twenty-fifth year. The fifth cuts the gum at the twentieth year, is entirely exposed soon after the fortieth, and is thrust out about the sixtieth year, by the advance of the sixth molar, which appears at about fifty years old, and probably lasts for half a century more. If others succeed this,--a seventh and even an eighth, as some a.s.sert,--these would carry on the Elephant's life to two or three centuries, in accordance with an ancient opinion, which is in some degree countenanced by modern observations.

To come back, then, to the case before us, since the fifth molar has its fore part much worn, and the posterior laminae scarcely yet protruded from the gum, it follows that this Elephant is now not far from the fortieth year of his life, a deduction which well agrees with the dimensions of his tusks, and his appearance of mature vigour.

Can you detect a flaw in this reasoning? And yet how baseless the conclusion, which a.s.signs a past existence of forty years to a creature called into existence this very day.

X.

PARALLELS AND PRECEDENTS.

(_Man._)

"Once, in the flight of ages past, There lived a Man,--and who was he?

Mortal, howe'er thy lot be cast, That man resembled thee."--MONTGOMERY.

We have knocked at the doors of the vegetable world, asking our questions; then at those of the lower tribes of the brute creation, and now at those of the higher forms; and we have received but one answer,--varying, indeed, in terms, but essentially the same in meaning,--from all. And now we have one more application to make; we have, still in our ideal peregrination, to seek out the newly-created form of our first progenitor, the primal Head of the Human Race.

And here we behold him; not like the beasts that perish, but--

"Of far n.o.bler shape, erect and tall, G.o.dlike erect, with native honour clad, In naked majesty, as lord of all."

The definitive question before us is this: Does the body of the Man just created present us with any evidences of a past existence, and if so, what are they? And that we may rightly judge of the matter, we will, as on former occasions, call in the aid of a skilful and experienced physiologist, to whom we will distinctly put the question.

_The Physiologist's Report._

In replying to your inquiry concerning the proofs of a past existence in the Man before me, I must treat of him as a mere animal,--a creature having an organic being.

And, first, I find every part of the surface of his body possessing a nearly uniform temperature, which is higher than that of the surrounding atmosphere. There is, moreover, on all parts of the body, a tinge of redness, more or less vivid in certain regions. The heat, and the carnation tinge, alike indicate the presence of blood, arterial blood, diffused throughout, and, in particular, occupying the capillaries of the superficial parts. Every drop of this blood is preceded and succeeded by other drops, every one of which has been impelled out of the heart by its constant contractions.

But the very existence of this blood supposes the pre-existence of chyle and lymph, out of which it has been constructed. The chyle was formed out of chyme, changed by the action of the pancreatic and biliary secretions. Chyme is food, chemically altered by the action of the gastric juice. So that the blood, now coursing through the arteries and veins, implies the previous process of the reception of food. And these pancreatic and biliary secretions, which are essential to the conversion of chyme into chyle,--and therefore into blood,--do you ask their origin? They were prepared, the one by the pancreas, the other by the liver, from blood already existing,--blood _previously formed_ of chyle with the addition of bile, &c.--and so indefinitely.

Again, the blood in these capillary arteries is of a bright scarlet hue, which it derives from its being charged with oxygen. This it received in the _lungs_, parting at the same time with the carbon which it had taken up in its former course. The lungs then must have existed _before_ the blood could be where and what it is, viz. arterial blood in the capillaries of the extremities; before it was driven out of the heart, since it was transmitted from the lungs through the pulmonary veins into the heart, thence to be pumped into the arterial system.

But since all the tissues of the body are formed from the blood, the lungs were dependent on already-existing blood for their existence. And as the formative and nutrient power is lodged exclusively in _arterial_ blood, the very blood out of which the lungs were organized was dependent on lungs for oxygenation, without which it would have been effete and useless.

Here then is a cycle of which I cannot trace the beginning.

But further. On the extremities of the fingers and of the toes, there are broad h.o.r.n.y _nails_. These I trace down to the curved line where they issue from beneath the skin, and whence every particle of each nail has issued in succession. They are composed of several strata of polygonal cells, which have all grown in reduplications of the skin, forming compressed curved sheaths (_follicles_); stratum after stratum of cells having been added to the base-line, as the nail perpetually grew forwards. About three months elapse from the emergence of a given stratum of cells, before that stratum becomes terminal; and therefore each of these twenty-four finger- and toe-nails is a witness to three months' past existence.

[Ill.u.s.tration: GROWTH OF HAIR (_magnified_).]

The head is clothed with luxuriant _hair_, composed of a mult.i.tude of individual fibres, each of which is an epidermic appendage, essentially similar to the nails. Every hair is contained at its basal extremity in a delicate follicle, where it terminates around a soft vascular bulb, made up of blood-vessels and nerves. On the surface of this living bulb the h.o.r.n.y substance is continually secreted and deposited in layers, each of which in succession pushes forward those previously made, till the tip extrudes from the follicle of the skin, after which it continues to grow in the same way, as an external hair. The tip is gradually worn away; and thus the constant growth cannot, in general, cause it to exceed a certain given length. Each of the thousands of hairs with which this majestic head is clothed, bears witness to past time; and as the increase of hair is about an inch per month, and as this hair is about four inches in length, we have here thousands of witnesses to at least four months of previous history.

The bones which make up the firm and stately fabric about which this human body is built, are no productions of a day. Long before this they existed in the form of cartilages. In these, minute arteries began to deposit particles of phosphate of lime, around certain centres of ossification, doing their work in a determinate order, and in regular lines, so as to form continuous fibres. These fibres, aggregated, and connected by others, soon formed a texture of spicula or thin plates.

Now take as an example a cylindrical hollow bone, as that of the thigh.

Here the spicula were arranged longitudinally, parallel to the axis of the bone: preserving the general form of the cartilage which const.i.tuted its scaffolding.

But the bone required a progressive increase in size. In its early state, moreover, it was not hollow, but solid. Changes must have taken place to bring it to its present dimensions and condition. These were effected by the actual removal of some parts, simultaneously with the deposition of others.

At a certain stage of ossification, cells were excavated by the action of the absorbent vessels, which carried away portions of bony matter lying in the axis of the cylindrical bone. Their place was supplied by an oily matter, which is the marrow. As the growth proceeded, while new layers were deposited on the outside of the bone, and at the end of the long fibres, the internal layers near the centre were removed by the absorbent vessels, so that the cavity was further enlarged. In this manner the outermost layer of the young bone gradually changed its relative situation, becoming more and more deeply buried by the new layers which were successively deposited, and which covered and surrounded it; until by the removal of all the layers situated near to the centre, it became the innermost layer, and was itself destined in its turn to disappear, leaving the new bone without a single particle which had entered into the composition of the original structure.[87]

These processes have been the slow and gradual work of years, of the lapse of which years the bones are themselves eloquent witnesses.

Within the mouth there are many _teeth_. I will not now speak of their exact number, nor of some other particulars concerning them, because I mean to return to them presently; but I look only at their general structure and origin. Each tooth consists of three distinct parts, the central portion, which is _ivory_; the exceedingly hard, polished, gla.s.sy coat of the crown, which is _enamel_; and a thin layer of bone around the fang, which is the _cement_.

Before either of these appeared, a minute papillary process of vascular pulp was formed in a cavity of the jaw. Over the pulp was spread an excessively thin membrane, which secreted from the blood, and deposited, a thin sh.e.l.l of bony matter, or ivory, moulded on the form of the pulp.

Successive layers of ivory were then added, from within; the pulp diminishing in a corresponding ratio. The cavity of the jaw at the same time deepened, and the pulp lengthened downward into the s.p.a.ce thus provided; layers of bony substance being gradually deposited upon it, as above.

[Ill.u.s.tration: SECTION OF HUMAN TOOTH (_magnified_).]

The cavity itself was lined with a thick vascular membrane, united to the papilla at its base. Within the s.p.a.ce lying between this membrane and the pulp, there was deposited from the wall of the former a soft, granular, non-vascular substance, known as the enamel organ. The cells on the inner surface of this substance then took the form of long, sub-parallel prisms, set in close array, perpendicular to the surface of the tooth. Earthy matter was progressively deposited in them, by which they became the exceedingly dense and hard enamel of the crown. The cement of the fang was then formed by a slight modification of the process which had produced the enamel.

Here, then, are several distinct and important processes, effected in regular and immutable succession, each requiring time for its performance, and all undeniably witnessed-to by the structure of every tooth here seen.

As I have thus proved the _fact_ of life existing in this human body for some time previous to the present moment, I now proceed to inquire how far its structure may throw light on the _actual duration_ of that past life. How far can we ascertain its chronology?

The stature of the Man before me is about six feet. An infant at birth is from eighteen to twenty-one inches in length. At ten years old the average stature is about four feet. Six feet may be taken as the full adult height of man; and this is attained from the twenty-first to the twenty-fifth year. The stature of this individual would therefore indicate an age not less than twenty-one years.

On the front of the throat I perceive a strongly-marked, angular prominence, formed by the union of the two plates of the thyroid cartilage. The prominence of this angle is due to the enlargement of the larynx; and it is accompanied by a deepening of the pitch of the voice, producing the full rich sounds that we have this instant heard, as the Man chanted his song of praise. These tones, and this projection of the thyroid cartilage, are equally distinctive marks of p.u.b.erty, and do not appear till about the sixteenth or seventeenth year.

The chin, and sides of the face, are clothed with a dense bush of crisp hair,--the beard. This is a distinctive mark of the adolescent period, and may be taken as indicating an age not less than twenty years.

On again examining the mouth, I find the teeth are thirty-two in number; viz., four incisors, two canines, four pre-molars, and six true molars, in each jaw. None of these existed (at least visibly) during the first seven years of life; in that period they were represented by the milk-teeth of infancy. The appearance of the middle pair of incisors occurred at about the eighth year; the lateral incisors at nine; the first pre-molars at ten; the second at eleven; the canines at about twelve; the second molars at thirteen or fourteen; and the third molars, or _dentes sapientiae_, at about seventeen or eighteen.

The state of the dent.i.tion, then, points to an age certainly not less than the period just named. How much more it may be, we must gather from other sources.

I come now to certain phenomena which are not appreciable to us on mere external examination; but which I am able with certainty to predicate.

And the first of these is the proportion of arterial to venous blood in the capillaries. In infancy, the arterial capillaries contain far more blood than the capillary veins; in old age, the proportion is exactly reversed; whereas, in maturity, the ratio is just equal. Now, here there is a very small preponderance of arterial blood, indicating a period but slightly remote from maturity on the side of youth; well agreeing with the conclusion arrived at from previous premises, of some twenty to five-and-twenty years.

Other and more marked manifestations occur in the condition of the skeleton. In the spine, I find _the spinous and transverse processes_ of the several vertebrae are completed by separate _epiphyses_, the ossification of which does not commence till after p.u.b.erty, and the final union of which with the body of the bone does not occur till about the age of twenty-five years.

Each _vertebra_, moreover, has attained a smooth annular _plate_ of solid bone, covering a surface that was previously rough and fissured, which is invariably added at the same period.

The _ossification of the sacrum_ also has reached its culminating point.

At the age of p.u.b.erty, the component vertebrae began to unite from below upwards, and the two highest have now coalesced; which also marks a period of life not earlier than the twenty-fifth year. The whole united ma.s.s, moreover, is furnished on each side with thin bony plates, the appearance of which is no less characteristic of the same age.

Each of the _ribs_ is here furnished with two _epiphyses_, one for the head and the other for the tubercle; the ossification of these began soon after p.u.b.erty; but their union with the body of the bone, as presented here, has taken several years to accomplish.

To come to the limbs, we find the _shoulder-blade_ presenting three _epiphyses_, one for the _coracoid_ process, one for the _acromion_, and one for the lower angle of the bone, the ossification of which begins soon after p.u.b.erty, their union with the body of the bone taking place between the ages of twenty-two and twenty-five years. The _clavicle_ has an _epiphysis_ at its sternal end, which begins to form between the eighteenth and twentieth years, and is united to the rest of the bone a few years later. The consolidation of the shoulder-bone (_humerus_) is completed rather earlier; the large piece at the upper end, which is formed by the coalescence of the ossific centres of the head and two tuberosities, unites with the shaft at about the twentieth year; whilst its lower extremity is completed by the junction of the external condyle, and of the two parts of the articulating surface (previously united with each other), at about the seventeenth year, and by that of the internal condyle in the year following. The superior _epiphyses_ of the arm-bones (_radius_ and _ulna_) unite with their respective shafts at about the age of p.u.b.erty; the inferior, which are of larger size, at about the twentieth year. The _epiphyses_ of the _metacarpal_ and _phalangeal bones_ (those of the hand and fingers) are united to their princ.i.p.als at about the twentieth year. In the _Lower Extremities_, the process of ossification is completed at nearly the same periods as that of the corresponding parts of the Upper. The consolidation of the hipbones (_ilium_, _ischium_, and _pubis_) to form the _os innominatum_, by the ossification of the triradiate cartilage that intervenes between them in the socket of the thigh (_acetabulum_), does not take place until after the period of p.u.b.erty; and at this time additional _epiphyses_ begin to make their appearance on the crest of the _ilium_, on its anterior inferior spine, on the tuberosity of the _ischium_, and on the inner margin of the _p.u.b.es_, which are not finally joined to the bone until about the twenty-fifth year.[88]