I.-Essential Points of Difference between the Larynx of the Negro and that of the White Man. By GEORGE DUNCAN GIBB, M.A., M.D., LL.D., F.G.S., F.A.S.L., Member of the Royal College of Physicians, Assistant-Physician and Lecturer on Forensic Medicine, Westminster Hospital, etc. (Read January 31st, 1865.)

IN prosecuting some recent researches into the minute anatomy of the human larynx, my observations were extended to an examination of that part of the organism in the Negro. I had already made myself familiar with the elements, entering into the formation of the same part in white people, by the dissection of many hundred larynges, and was therefore prepared to note any deviation that might present itself in the coloured race. In prosecuting this inquiry, no difference was anticipated by me beforehand between the larynx of white and black people; more especially as some years back my dissections had included a considerable number of those from the black race; and at that time whatever peculiarities may have been noticed, they were not then considered of such importance as to attract the attention of scientific men.

The great impulse, however, which has been given to the study of the upper air passages within the last four years, through the revival of the laryngoscope, has led to the most careful scrutiny of every part of the larynx; and peculiarities and deviations that may have been heretofore looked upon as

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notably visible. Their presence, therefore, is exceptional in the white man.

On either side of the larynx we see the vestibule of the glottis ; the superior thyro-arytenoid ligaments, or false vocal cords; the ventricles of Morgagni; and, lastly, the true vocal cords.

These last, namely, the real vocal cords, are seen flat and horizontal, of a white colour tinged with a shade of grey. On closure of the glottis, or space between them, the floor formed by their union continues flat and smooth, without any irregularity beyond the almost imperceptible vibrations produced by the efforts at phonation acting on their brilliant pearly, free borders.

The external border of each vocal cord is bounded by the elliptical aperture of the ventricle of Morgagni, the floor of which cavity is continuous with the horizontal plane of the vocal cords, with a slight inclination upwards and outwards. It follows, therefore, that the ventricle, or sinus, is situated wholly above the plane of the vocal cords, as presented to our view in the laryngeal mirror, and is, for the most part, placed quite external to the vocal cord, thus preventing our seeing into its interior. This last-named circumstance must not be forgotten. These appearances are shown in the woodcuts, Nos. 1 and 2.

Fig. 1. a a. The horizontal and flat vocal cords, bounding a narrow triangular glottis; on the outer side of each cord is seen a narrow opening into the ventricles of the larynx. b b. The arytenoid cartilages. d. The epiglottis. c. Back of the tongue.

Fig. 2. a a. The horizontal and flat vocal cords, bounding a lozenge-shaped glottis; on the outer side of each cord is seen the narrow opening into the ventricles, as in fig. 1. b b. The arytenoid cartilages. d. The epiglottis. c. Back of the tongue.

Having said thus much of the white man, we will now inquire, What do we see in the Negro? Unquestionably, the same parts as in his white brother, but with certain deviations in form and superadded parts, which demand our attention.

And firstly, of the cartilages of Wrisberg. These rare bodies in the white are, I may truly say, invariably present in the black race, and stand out as conspicuous objects in the laryngeal mirror, their reflection being readily visible to every experienced eye. They resemble small adipose masses the size of a small pea, and look not unlike a suppurating surface on the point of bursting, situated in the aryteno-epiglottidean fold, midway between the epiglottis and arytenoid cartilage. They are present in the old and young of both sexes; probably more fully developed in the prime of life, although seen tolerably large in the comparatively young, or those who have arrived at the age of puberty. Their constant presence in the Negro, and their frequent absence or rudimentary condition in the white man, prove them to be characteristic of the former; as much so, in all probability, as that the skin is black in the Negro from the presence of a distinct pigment in the rete mucosum, which is absent in the white man.

If no other point of difference between the two races was found than the presence or absence of this small cartilage, it is of itself alone of sufficient significance to distinguish the one from the other.

On extending our comparison further, we shall find that whilst the true vocal cords in the white race possess a horizontal or flat surface, almost in a plane with the general strike of the ventricles,—a characteristic, I may assert, to be never varying, and always constant, unless altered by disease. In the Negro, the plane of the vocal cords is more or less oblique from within outwards; i. e., their internal free border is elevated at a higher angle than their external or attached border, thus giving to each vocal cord a slanting or shelving direction outwards and downwards.

This obliquity of the cords varies in degree and extent, but can be generally distinguished; the contrast, however, is striking between the flat horizontal surface and the oblique,

and this is to be seen especially where the point of origin of the two cords is long, as represented in woodcut, No. 3.

Fig. 3. The larynx of the Negro. a a. The oblique vocal cords, between which is a lanciform glottis. On each side of the shelving and oblique cords, e e, is the long and narrow elliptical opening of the pendent ventricles. bb. The arytenoid cartilages. c c. The cartilages of Wrisberg, absent in figs. 1 and 2. d. The epiglottis, which is the same in both races. f. Back of the tongue.

In the larynx of the white man, we observe the margins of the openings leading into the ventricles which exist on either side, yet immediately above the true vocal cords. The upper margin of one of these openings is placed at a right angle to the plane of the vocal cord, and is generally perpendicular to the outer border of the same vocal cord; whilst the lower margin is at the outer boundary of the cord, unless during the act of retraction of the cord outwards. In other words, the ventricle is situated external to, but immediately above the plane of the true vocal cords.

In the Negro, on the other hand, we observe a long and narrow elliptical opening (see e, fig. 3) which leads outwards and downwards right into the ventricle, the whole extent of which, to its very fundus, is visible in most black persons. The change of position in the ventricle is here most striking; for it hangs sidewise on the outer side of a shelving vocal cord in such a way that, if the cord were dry and a bead placed on