perhaps the pain has produced that other effect of spasmodic irritation of the nerves. At all events, movements occur; the limbs are thrown about, the head is tossed from side to side, and so on. Now, let the pain instantly cease. Mentally, the result is a great reaction, in fact a burst of pleasure; physically, there concurs the usual elation of the system, moving members among the rest. The movements that were going on when the pain ceased, receive a sudden accession of power out of the general fund, and are made all the more energetic. Apply this to a particular instance. A new-born animal lies on the ground uneasy. It knows nothing of the cause and as little of the remedy. The physical accompaniment of the state is a languid condition of the bodily members, supposing no acute stimulation of the nerves. Still the moving energies are not entirely subdued. The spontaneous tendencies, prompting now to one part, now to another, make it at last spring to its legs and commence a forward locomotion. With the locomotion, the uneasiness sensibly subsides. Say that the animal is thereby withdrawn from too great proximity to the fire. Now, every felt abatement of the uneasy sensation is a throb of pleasure, and carries with it the usual physical stimulation. The inevitable consequence is, that the locomotive movement accidentally begun shares in the heightened energy imparted to the system, concurrently with the relief from the pain, and is consequently quickened. If the relief still goes on, so does the stimulation, until the uneasy state has passed away even from the remembrance; at which stage no further increase takes place, and the animal, after giving full vent to the energy thus imparted, falls away again to the resting posture. If, however, in avoiding Scylla, the creature were to come upon Charybdis, the course would be reversed; a new pain encountered would have its effect in arresting action; a pain increasing at every step would accelerate the downward career of depression, until movement were no longer possible.

To take another example. An infant lying in bed has the painful sensation of chillness. This feeling has its usual

depressing accompaniments, and may or may not cause the convulsive outburst of pain, what we may term the characteristic emotional expression. At all events, spontaneous movements will arise, whether from natural healthy power, or from irritated nerves. In the course of these spontaneous movements, there occurs an action bringing the child into contact with the nurse lying beside it; instantly, warmth is felt, there is a throb of pleasure, and a concurrent stimulus to the physical system. The successful movement is sustained, and made more energetic, and the contact is kept up. Such would be the natural operation of the law that connects pleasurable relief with increased energy. The child twelve months old can perform this act by a true selective volition: the child of three days can do it only at random, and by the help of the principle we have been explaining. A process of acquirement has, I believe, occurred in the meantime, which is exemplified in the present volume (CONTIGUITY, Associations of Volition), and at still greater length in 'The Emotions and the Will' (WILL, Chap. II.).

29. There are various actions, commonly called Instincts, that are only phases or results of this fundamental property of mind. Self-preservation, implying the revulsion from pain and injury, and the appropriation of the means of subsistence, is an example of volition as now explained. We have apparently no original tendency to protect ourselves from injurious influences, if they do not affect us as pains, nor to lay hold of beneficial influences that give no present pleasure.

Certain special instances of early precaution against harm are often remarked upon, as a portion of the original provision of nature in our behalf. Thus the dread of falling is very strong in early life, and stimulates powerful efforts by way of prevention. But this is no other than an instance of volition in general. The remembrance of the acute pain of a past fall is a motive to preserve the stability of one's footing. And even still earlier, and before experienced hurts can operate as a warning, there is a severe and distressing

sensation in the sudden loss of support, which prompts us to exertion for restoring the firm position.

THE VOICE.

30. So deeply does the power of Speech enter into the operations of Mind-Feeling, Action, and Intelligence-that the mechanism of the organ deserves a full description.

I shall first make a few quotations from the Anatomy of the Voice.

'The upper part of the air passage (from the lungs) is modified in its structure to form the organ of voice. This organ, named the larynx, is placed at the upper and fore part of the neck, where it forms a considerable prominence in the middle line. It lies between the large vessels of the neck, and below the tongue and hyoid bone, to which bone it is suspended.'

The larynx is cylindrical at the lower part, where it joins the trachea (or windpipe), but it widens above, becomes flattened behind and at the sides, and presents a blunted vertical ridge in front.

'The larynx consists of a framework of cartilages, articulated together and connected by proper ligaments, two of which, named the true vocal cords, are immediately concerned in the production of the voice. It also possesses muscles, which move the cartilages one upon another, a mucous membrane lining its internal surface, numerous mucous glands, and lastly, bloodvessels, lymphatics, and nerves, besides cellular tissue and fat.'

Cartilages of the Larynx.-' The cartilages of the larynx consist of three single and symmetrical pieces, named respectively the thyroid cartilage, the cricoid cartilage, and the cartilage of the epiglottis, and of six others, which occur in pairs, namely, the two arytenoid cartilages, the cornicula laryngis, and the cuneiform cartilages. Of these, only the thyroid and cricoid cartilages are seen on the front and sides of the larynx (see fig. 11, p. 309); the arytenoid cartilages, surmounted by the cornicula of the larynx, together with the back of the cricoid cartilage, on which they rest, form the posterior wall of the larynx, whilst the epiglottis is situated in front, and the cuneiform cartilages on each side of the upper opening.'-QUAIN.

Confining ourselves as much as possible to the parts

CARTILAGES OF THE LARYNX.

307

immediately connected with voice, we need to refer principally to the thyroid and cricoid cartilages, the two arytenoid cartilages, the true vocal cords, and the muscles that move the cartilages and thereby affect the tension and the position of the vocal cords.

The thyroid (shield-shaped) cartilage (see fig. 10) is the largest of the pieces composing the larynx. It is formed by two flat lamellæ united in front at an acute angle along the middle line, where they form a vertical projection which becomes gradually effaced as it is traced from above downwards. The two lamellæ, diverging one from the other backwards, embrace the cricoid cartilage, and terminate posteriorly by two thick projecting vertical borders, separated widely from each other; hence the thyroid cartilage is altogether wanting behind. The angular projection on the anterior surface in the median line is subcutaneous, and is much more prominent in the male than in the female, being named in the former the pomum Adami.'

The cricoid cartilage, so named from its being shaped like a ring, is thicker in substance and stronger than the thyroid cartilage; it forms the inferior, and a considerable portion of the back part of the larynx, and is the only one of the cartilages which completely surrounds this organ. It is deeper behind, where the thyroid cartilage is deficient, measuring in the male about an inch from above downwards, but is much narrower in front, where its vertical measurement is only two lines and a half. The cricoid cartilage is circular below, but higher up it is somewhat compressed laterally, so that the passage through it is elliptical, its antero-posterior diameter being longer than the transverse.'

"The arytenoid (ewer-shaped) cartilages (fig. 11) are two in number, and perfectly symmetrical in form. They may be compared to two three-sided pyramids recurved at the summit, measuring from five to six lines (half an inch) in height, resting by their bases on the posterior and highest part of the cricoid cartilage, and approaching near to one another towards the median line. Each measures upwards of three lines in width, and more than a line from before backwards.'

The cartilages are bound together by ligaments, of which I omit the description. The appearance of the interior of the larynx is given as follows (see fig. 11):

'On looking down through the superior opening of the larynx (where it communicates with the pharynx above and is bounded by the epiglottis, &c.), the air passage below this part is seen to become gradually contracted, especially in its transverse diameter, so as to assume the form of a long narrow fissure running from before backwards. This narrow part of the larynx is called the glottis. Below it, at the upper border of the cricoid cartilage, the interior of the larynx assumes an elliptical form, and lower down still it becomes circular. The glottis is bounded laterally by four strongly marked folds of the mucous membrane, stretched from before backwards, two on each side, and named the vocal cords. The superior vocal cords are much thinner and weaker than the inferior, and are arched or semilunar in form; the inferior or true vocal cords are thick, strong, and straight. Between the right and left inferior vocal cord is the narrow opening of the glottis, named the rima glottidis, and sometimes the glottis vera or true glottis.'

FIG. 10.

The inferior or true vocal cords, by whose vibration the voice is produced, are two bands of elastic substance, attached in front to about the middle of the depression between the wings of the thyroid cartilage, and behind to the arytenoid cartilages; from this connexion they are called thyroarytenoid ligaments. They consist of closely arranged parallel fibres of that peculiar tissue occurring in some other parts of the body, named the yellow elastic tissue, being probably the most perfectly elastic substance of a ligamentous kind that nature has produced. India-rubber is em

• Side view of the thyroid and cricoid cartilages, with part of the trachea; after Willis.-8. Thyroid cartilage. 9. 9. Cricoid cartilage. 10. Crico-thyroid muscle. 11. Crico-thyroid membrane, or ligament. 12. Upper rings of the trachea.'-(QUAIN.)