80 



LACRYMAL ORGANS. 



hence, when the eye is open, the apex of the 

 angle formed by the inner canthus is broader 

 and to a much greater degree prolonged than 

 the outer; it is also rounded and turned down- 

 wards, but likewise in a much greater degree. 

 The margins bounding the secondary fissure 

 being destitute of cartilage are riot firm and 

 square but soft and rounded. 



Where the margin of either eyelid is con- 

 tinued into the margins bounding the secon- 

 dary fissure in question, there is observed on 

 slightly everting the eyelids a small promi- 

 nence, and in the apex of it a minute aperture, 

 larger however than those above mentioned of 

 the Meibomian follicles. The eminence is 

 called lacrymal papilla and the aperture lac?y- 

 mal point. 



The fissure is closed by the action of the 

 orbicularis muscle at the same time as the eye- 

 lids ; but its margins, especially at the lacrymal 

 papillae, come completely into contact before 

 they do. The space within the inner or nasal 

 canthus is called lacus lacrymalis. The lacry- 

 mal papillae and their points are turned in 

 towards it, ready to take up the tears as they 

 collect. 



At the bottom of the lacus lacrymalis, there 

 is seen a small reddish glandular body, the 

 lacrymal caruncle, and between the latter and 

 the white of the eye a semilunur fold of pink- 

 coloured conjunctiva. 



Eyelashes, Cilia* Fr. Cils; Ital. Leciglia; 

 Germ. Die Augenwimpern. Everyone knows 

 the conformation of the eyelashes. How that 

 they are stiff compressed hairs, increasing at 

 first in thickness from their root, then gradu- 

 ally tapering to their free and slender extre- 

 mity ; how that they spring from the anterior 

 edge of the palpebral margins ; how that those 

 of the upper eyelid are stronger and more nu- 

 merous than those of the lower; how that those 

 in the middle are longer than those towards 

 the corners of the eyelids; and how that those 

 of the upper eyelid are curved upwards and 

 those of the lower eyelid downwards, so that 

 their convexities regard each other. In regard 

 to the curvature it is to be remarked that it is 

 not gradually throughout the whole hair but is 

 betwixt the thickest part and the root. There 

 is another slight but variable curvature towards 

 the extremity. 



The skin of the eyelids is continuous with 

 and similar to that of the face, only some- 

 what more delicate. The skin of the upper 

 eyelid is more delicate than that of the lower. 



The eyebrows, supercilia, Fr. Les sourcils ; 

 Ital. Le sopraciglia; Germ. Die Augenbraunen 

 (Jig. 11). The external appearanceof the eye- 

 brows is too well known to require any particu- 

 lar description. Their prominence is produced 

 partly by the superciliary arches of the frontal 

 bone over which they lie, but principally by a 

 cushion of cellular and adipose tissue under- 

 neath the skin, together with the roots of the 

 hairs and muscular substance. The hairs of 

 the eyebrow are, generally speaking, directed 

 from within outwards, but internally, especi- 



* Cilia, quia oculos cclent ac tueantur. 



ally where they exist over the root of the nose, 

 they are inclined in the opposite direction. 

 Those immediately over the root of the nose 

 indeed cross each other. Besides the general 

 direction from within outwards of the majority 

 of the hairs of the eyebrows, it is to be re- 

 marked that the uppermost ones are inclined 

 downwards and the lowermost ones upwards, 

 so that they are raised into a kind of ridge 

 along the middle line of the eyebrow, an ar- 

 rangement which presents a pleasing appear- 

 ance of regularity. The eyebrows are capable 

 of very free motions, and these are in close 

 connexion with the affections of the mind ; 

 hence the eyebrows have always been con- 

 sidered a very important physiognomonical 

 feature. The movements of the eyebrows 

 are effected by muscles inserted into their skin. 

 These muscles are: the frontalis, which elevates 

 the eyebrows ; the upper and outer fibres of 

 the orbicularis palpebramm, which depress 

 them, and the corrugatorsupercilii, which draws 

 them inwards. For their description, see 

 article FACE. 



The eyelids act in conjunction with the iris 

 on many occasions ; thus, in a weak light and 

 in the act of looking at distant objects, the 

 eyelids are widely opened at the same time that 

 the pupil is dilated ; when the eye is exposed 

 to a strong light, on the contrary, or in looking 

 at near objects, the palpebral fissure is con- 

 tracted along with the pupil. In sleep com- 

 plete closure of the eyelids is associated with 

 very great contraction of the pupil.* 



Fig. II. 



The eyelids nf the left side widely opened, seen from 

 without. (From Soemmerring . ) 



a a, The broad free margins of the eyelids, with 

 the mouths of the Meibomian follicles. 



b, Outer canthus. 



c, Inner canthus. 



d, Lacrymal papilla and lacrymal point of upper 



eyelid. 



e, The same of the lower eyelid. 



f, Lacrymal caruncle, and ry, semilunar fold, at the 



bottom of the lacus lacrymalis, which is the 

 space within the fissure of the inner canthus. 



h h, The orifices whence the eyelashes have been 

 plucked out. 



i, Eyebrow. 



* See farther on this subject, Tourtnal.Ueber die 

 Function der Au^enlider beim Si Inn. in Muller's 

 Archiv, No. iii. 1838. 



