Chapter 3

=The Windpipe= (pl. I, W).--Having examined the bellows of our vocal organ, we next notice the windpipe, by means of which the air is carried into and out of the lungs. It is an elastic tube kept open by 18 or 20 rings which do not quite meet at the back. It enters the lungs by means of two smaller tubes, which in their turn branch out very much like the roots of a tree, until their ramifications end in the microscopic cells of the lungs. The windpipe is capable of being slightly elongated or shortened, and narrowed or widened, and its interior is covered with a mucous membrane, which, as its name implies, is continually kept in a moist state.

=The Voicebox, or Larynx= (pl. V) may be described as resembling a funnel, the upper part of which has been bent into a triangular shape. Its front corner (pl. V, 1) may be both seen and felt in the throat, and the general position of the voicebox is thereby at once indicated. The framework of the voicebox consists of five parts. 1st. The Ring cartilage (pl. V, 2) is so named on account of its general resemblance to a signet ring. It is narrow in front, and has the part corresponding to the seal behind; the upper border (pl. V, 8, 4) rises very considerably towards the back, where it is about an inch high. 2nd. Riding upon this, as it were, with its hollow part towards the back, is the Shield cartilage (pl. V, 5), which consists of two plates united in front at an angle which forms the prominence referred to just now as that corner of the triangular funnel (pl. V, 1) which may be both seen and felt in the throat, and which is commonly called the Adam's Apple. It protects the interior and more delicate parts of the voice apparatus, from which circumstance it derives its name of shield cartilage. The plates of the shield have each at the back two horns, the upper and the lower. With the upper horns (pl. VI, 1, 2) the shield cartilage is attached by means of bands (pl. VI, 6, 7) to the corresponding projections (pl. VI, 4, 5) of the tongue-bone (pl. VI, 3), which has the shape of a horseshoe. With the lower horns (pl. V, 8), of which on our diagram we can only see one, it moves upon the ring cartilage as upon a hinge (pl. V, 9).

This is a very particular point, and I beg the reader particularly to notice that if the shield cartilage (pl. V, 5) were gradually drawn downwards and forwards, the space which we now see between the shield and the ring (pl. V, 10) would get smaller and smaller, until at last it quite disappeared; and the distance between the front of the shield (pl. V, 1) and the highest part of the back of the ring (pl. V, 4) would be increased.

I may observe here that authorities differ as to whether the shield moves upon the ring, or the ring upon the shield, and that some maintain the one is drawn down while the other is tipped upward. It is sufficient for our purpose, however, that a movement as upon a hinge takes place, whereby, as explained just now, the distance between the front of the shield and the highest part of the back of the ring is increased.

3rd. =The Lid= (pl. V, 11) is an elastic cartilage which serves to close the voicebox in the act of swallowing, in order to protect it against any intruding foreign substances. The food we take has to pass over it, and it sometimes happens, when the lid has not been pulled down tight enough, that a particle of food enters the voicebox, in which case we say it has "gone the wrong way," and there is then no peace until the intruder has been got rid of, generally by a violent fit of coughing.

The lid, it is true, is not the only means of protection which the voicebox possesses. Professor C. J. Eberth, for instance, mentions (Archiv für pathol: Anatomie, vol. lxiii., p. 135, Berlin, 1868) the case of a woman who, upon dissection, was found to be entirely without the free upper part of the lid, which could alone cover the voicebox. She had never experienced any difficulty in swallowing, and it is therefore clear that with her the closing of some of the parts immediately below was sufficient to prevent the food from getting into the voicebox. But "the exception proves the rule," and in spite of this and other similar cases, the fact remains that the lid is obviously the first and most natural protector of the voicebox.

4th and 5th. We have thus far become acquainted with three cartilages out of the five. Let us now remove one plate of the shield, as though cutting it off with a knife (pl. VII, 1 and 2), in order that we may look inside and see the remaining two cartilages which have hitherto been hidden by it. These are--

=The Pyramids= (pl. VII, 1 and 2), so called because of their shape. Their bases are triangular and hollowed out; their sides taper upwards and terminate in points which are bent slightly backwards, and they have each two projections, one pointing forwards (pl. VII, 3) and the other outwards and backwards (pl. VII, 4). It will be convenient to have a special name for the projections pointing outwards and backwards, which we will therefore call the Levers.

The Pyramids are attached with their hollow bases to the borders of the ring (pl. VII, 5), and they are capable of executing rotary movements with surprising freedom and rapidity. Their inner sides may be made to run parallel or to diverge. In addition to this they can be drawn towards each other, or away from each other, so that their summits may either be widely separated or brought close together.

=The Vocal Ligaments= are two ledges of elastic tissue covered with a very delicate membrane. Each one of them is connected along its whole length, on one side, with the shield cartilage. The vocal ligaments are attached by their hinder ends to those little projections of the pyramids which point forwards (pl. VII, 3, 3), and by their front ends to the centre of the shield (pl. VII, 6), where the two plates meet under a more or less acute angle.

These vocal ligaments are generally called the vocal cords, but this term is misleading, as it implies strings like those, for instance, of the violin, which are attached only at either end and are free at every other point. This, however, as we have just seen, is not the case, the "Cords" being free only along their inner edges. The name "Vocal Bands," which German physiologists have substituted for "Vocal Cords," does not mend the matter, as it is open to exactly the same objections. The term "Vocal Lips," also used by some writers, is, in my judgment, the most unfortunate of all, because it conveys a totally wrong idea of these parts, as will be seen from a description in another chapter of their movements in the act of singing. I have, therefore, sought for a word which, as a proper description of the thing it is to designate, shall always call a correct image to the reader's mind, and as I cannot find a better one than "Ligament," I have adopted it. I shall consequently in these pages always speak of the tone-producing element as the "Vocal Ligaments."

The vocal ligaments, having met, are struck by the air blown against them from below, and being elastic they yield, allowing themselves to be forced upwards. A little air is thereby set free, and the pressure from below diminished, in consequence of which the vocal ligaments resume their former position, and even move a little more downwards. The renewed pressure of the air once more overcomes the resistance of the vocal ligaments, which again recede as soon as another escape of air has taken place, and this process is repeated in rapid and regular succession. In this manner, and in this manner alone, is vocal tone produced, whether it be called chest, falsetto, head, or by any other name.

There are still some writers who teach a different doctrine. For instance, Miss Sabilla Novello, in her "Voice and Vocal Art," embodied in the "Collegiate Vocal Tutor," published by Novello, Ewer, and Co., says on p. 9, that "The head voice results from the upper [_i.e._, the false] vocal cords" (these we shall see presently), and on page 13, that the falsetto tones "are created principally by the action of the trachea [windpipe] and not by that of the vocal ligaments." Another writer, Mr. Rumney Illingworth, in a paper "On the Larynx and its Physiology," read before the Royal Medical Society of Edinburgh, on March 3rd, 1879, and communicated to "The Students' Journal and Hospital Gazette" (Vol. IV., No. 91, p. 151), says that "The falsetto voice is produced by the laryngeal sacculi [the pockets of the voicebox, which will be described further on] acting in the same way as a hazel-nut can be made to act as a whistle, when the kernel has been extracted through a small hole in the shell; or as part of the cavity of the mouth acts in whistling." I shall refer to these theories again as the opportunity for their proper discussion arises; for the present I will quote a few authorities on the subject.

Dr. CARPENTER, in his "Human Physiology," eighth edition, page 914, says, "The true theory of the voice may now be considered as well established in regard to this essential particular that the sound is the result of the vibrations of the vocal cords," &c.

Professor MARSHALL, in his "Outlines of Physiology," page 255, says: "Experiments on living animals show that the vocal cords are alone the essential organs for the production of voice, for so long as these remain untouched, although all the other parts in the interior of the larynx be destroyed, the animal is able to emit vocal sounds.... The existence of an opening in the larynx of a living animal, or of man, _above_ the glottis [glottis means the vibrating element of the voicebox] in no way prevents the formation of vocal sound; such an opening if situated in the trachea [windpipe] causes total loss of voice, but by simply closing it, vocal sounds can again be produced. Such openings, in man, are met with, either as the results of accidents, of suicidal attempts, or of operations performed on the larynx or trachea for the relief of disease."

Dr. TOBOLD, Professor in the University of Berlin, in his "Laryngoscopie and Kehlkopf Krankheiten" (Laryngoscopy and Diseases of the Larynx), p. 131, says, "Soft palate, lid, pockets, and pocket-bands are not directly active in the production of either chest or falsetto tones; they only modify the tone produced in the glottis."

Dr. LUSCHKA, Professor in the University of Tubingen, in his great work "Der Kehlkopf des Menschen" (The Human Larynx), says in the introduction: "Only the vocal cords, with the slit they form, have specifically functional signification, in a narrower sense, of a voice apparatus, as the parts of the larynx which lie under and over them have no material and deciding influence on the production of sound."

I will bring my quotations to a close with the following, which seeks to prove the contrary. Dr. C. B. GARRETT ("The Human Voice," J. and J. Churchill, London, 1875, p. 17) says, "It is recorded that the larynx of a blackbird was removed by severing the windpipe just below it; that the poor 'thing continued to _sing_, though in a feebler tone.' This proves that notes can be formed _behind the instrument_ and before the air reaches it." This argument, however, is of no value, because it so happens that birds have two larynges, one at the bottom and the other at the top of the windpipe. Dr. Garrett seems not to have been aware of this fact.

The vocal ligaments in the adult male are, in a state of rest, about three-quarters of an inch long, and in the female about half an inch. I pointed out before that the vocal ligaments are attached in front to the shield (pl. VII, 6) and behind to the pyramids (pl. VII, 3, 3). Let it now be borne in mind--1st, That the pyramids, in their turn, are fastened to the upper border of the ring cartilage; and 2nd, That by drawing the shield downwards and forwards upon the ring, the distance between the upper border of the ring (pl. VII, 5) and the front of the shield (pl. VII, 6) is increased, and it will be easily seen that this movement must of necessity have the effect of stretching the vocal ligaments.

This drawing of the shield downwards and forwards upon the ring is brought about by a pair of muscles ascending on either side, in the shape of a fan, from the ring to the shield cartilage (pl. VIII, 1, 2). These muscles we name the "Ring-Shield Muscles." In opposition to them there is another pair inside the shield, running parallel with the vocal ligaments (pl. IX, 1, 2, 3). They are attached (like the vocal ligaments) in front to the shield cartilage and behind to the pyramids. These muscles we will call the "Shield-Pyramid Muscles." They counteract the ring-shield muscles, and having overcome their resistance, pull the shield cartilage up again, thereby, of course, relaxing the vocal ligaments. The ring-shield muscles, therefore, _stretch_ the vocal ligaments and the shield-pyramid muscles _relax_ them. The shield-pyramid muscles have an additional function--that of pressing together the vocal ligaments, under certain circumstances, thereby narrowing the opening between them. They have therefore been, in these later days, called the Sphincter[G] muscle of the glottis. They have also been called the Vocal Muscles, since they play so important a part in the formation of all vocal tone that a paralysis of them causes total loss of voice.

It may be observed here that it is impossible to imitate, in the dead subject, the contraction of the vocal muscles. All conclusions, therefore, drawn from experiments upon exsected larynges, with regard to tone-production in living man are necessarily quite untrustworthy, and cannot for one moment be admitted as evidence against observations made upon singers with the laryngoscope.

These two pairs of muscles, then, namely the ring-shield muscles (pl. VIII, 1, 2) and the shield-pyramid muscles (pl. IX, 1, 2, 3) by stretching, slackening, and compressing the vocal ligaments, mainly govern the pitch of the tones produced by their vibrations. The ring-shield muscles receive some assistance in stretching the vocal ligaments from another quarter, of which we shall speak later on.

We have now had a look at the vocal ligaments, and we have seen by what means they are put on the stretch. As, however, in a state of repose these ligaments diverge behind, they must be brought parallel to each other before they are ready for the production of sound. Let us, therefore, in order to explain how this is done, imagine that we have cut off that part of the pyramids which is standing out above the vocal ligaments (pl. VII), and let us now have a look at these parts from above. You see the ligaments (pl. XA, 1, 2), a section of the pyramids (pl. XA, 3, 4), and uniting these an elastic band (pl. XA, 5). The space between these parts is commonly called the Glottis, but as this appellation belongs more properly to the vocal ligaments, it is manifestly wrong to give the same name to the _space_ which they inclose. This space should be distinguished as the "_Chink_ of the Glottis" or the "Vocal Chink."

I have been blamed for making this distinction in the face of almost universal usage. But I can point to the great anatomist Professor Luschka as having set the example, and while it is true that in most physiological works "Glottis" is used for the _slit_ between the vocal ligaments, yet the appellations "Rima glottidis" and "Aperture of the glottis" are also employed for the same thing. Medical men, moreover, speak of "Spasm of the glottis," and singing masters of the "Shock of the glottis," which terms are clearly quite meaningless when applied to a space.

Dr. Garrett says, on page 12 of the book quoted before, that "The upper portion of the larynx above the false vocal cords is termed the glottis." He might as well say, "The upper portion of the face above the nose is termed the mouth." I really should not notice so astounding a statement were it not made by one signing himself an M.D., and published by so eminent a firm of Medical publishers as Messrs. J. and A. Churchill.

On plate XI you see all parts in a state of rest. To the levers of the pyramids (pl. XI, 1, 2) a pair of muscles is attached, the bases of which are fixed upon the back of the ring cartilage below (pl. XI, 3, 6, 3). The action of these "Back Ring-Pyramid Muscles" (pl. XI, 4, 1 and 5, 2) is to contract as soon as we take breath, thereby drawing together the pyramids _behind_ and separating them _in front_, at the same time stretching the elastic band behind (pl. X, A, 5). By this movement the chink of the glottis is thrown _wide open_ into the shape depicted on pl. X, B. During expiration these relax, the elastic band contracts, and the vocal chink resumes the shape as on pl. XI. These movements go on from the beginning of our lives to the end, whether we are asleep or awake, with more or less vigour, according as we take a slight or a deep inspiration. The back ring-pyramid muscles (pl. XI, 4, 1 and 5, 2), have consequently the all-important function of keeping open the gate through which the air we breathe enters the lungs. They have, therefore, been poetically called the "Guardians of the Portal of Life." By their action of pulling the pyramids backwards, they also assist the ring-shield muscles (pl. VIII, 1, 2) in stretching the vocal ligaments.

* * * * *

In opposition to these "Opening Muscles" there is another pair rising from the side borders of the ring (pl. XI, 3, 3) which are fastened to the front part of the levers of the pyramids (pl. XI, 1, 2), serving to draw together their front projections to which the vocal ligaments are attached, and which are thereby brought parallel with each other.

These "Side Ring-Pyramid Muscles" (pl. XI, 3, 1 and 3, 2; see also pl. IX, 5, 4) are assisted by a single muscle uniting the pyramids behind the elastic band which we have already noticed. This muscle we will call the "Pyramid Muscle" (pl. XI, 7). By the united action of the muscles which have just been described the vocal chink is thrown in the shape shown on pl. X, C, and the vocal ligaments are now in a proper position for the production of tone.

* * * * *

Before proceeding any farther it will be well if we once more glance at the muscles with which we have become acquainted, so that we may be quite sure about their functions.

MUSCLES:

I. GOVERNING THE SHAPE OF THE VOCAL CHINK.

The Back Ring-Pyramid} OPENING Muscles } THE VOCAL CHINK.

THESE ARE OPPOSED BY--

The Side Ring-Pyramid } Muscles, and the Pyramid} CLOSING Muscles, assisted by the} THE VOCAL CHINK. Shield-Pyramid Muscles }

II. GOVERNING THE PITCH OF THE TONES.

The Ring-Shield Muscles, } STRETCHING assisted by the Back Ring-Pyramid } Muscles } THE VOCAL LIGAMENTS.

THESE ARE OPPOSED BY--

The Shield-Pyramid } SLACKENING Muscles } THE VOCAL LIGAMENTS.

=The Pocket Ligaments= (called "False Vocal Cords," pl. XII, 1 and 2) are a pair of horizontal projections running above and parallel with the vocal ligaments (pl. XII, 3 and 4). The pocket ligaments are, like the vocal ligaments, attached in front to the shield and behind to the pyramids. They may be described as two ledge-shaped pads mainly formed of glands. They are very sensitive and movable, and ready on the smallest incitement to meet with great rapidity in order to protect the vocal ligaments from any harm. They must, therefore, be chiefly regarded as safeguards of the vocal apparatus, though it is probable that by breaking the stream of air passing through the chink of the glottis, they also exercise considerable influence upon the _quality_ of the tone emitted. It may be affirmed, however, without the slightest hesitation, that they have absolutely nothing to do with the _production_ of tone. We shall see these glandular ledges again during our observations upon the living subject, and I shall therefore say no more about them at present.