LACRYMAL ORGANS. 



91 



of the lowest spongy bone and the posterior 

 margin of the groove in the superior maxillary, 

 constituting the anterior and outer walls. The 

 internal wall of the osseous nasal canal is 

 formed superiorly by a continuation of the 

 osseous surfaces composing the lacrymal groove. 

 Below, it is formed, in front, by a farther con- 

 tinuation of one of these surfaces, viz. that of 

 the superior maxillary bone, and behind by a 

 thin plate of the lowest spongy bone, the nasal 

 or lacrymal process of the lowest spongy bone, 

 which rises to join the inferior edge of the 

 lacrymal. The anterior edge of this process 

 of the spongy bone joins the posterior edge of 

 the lower part of the lacrymal surface of the 

 nasal process of the superior maxillary. The 

 line of junction is thus the continuation of that 

 at the bottom of the lacrymal groove. 



Lacrymal papillae, points and canalicules. 

 (Fig- 15.) At the inner extremity of the ciliary 



Continuation of Figure 11, showing the relative situa- 

 tion of the upper mass of the lacrymal gland, and 

 the exact shape of the derivative lacrymal passages. 

 (From Soemmerring.) 



a, b, c, d, superior and inferior lacrymal canali- 

 culi ; a, a, lacrymal points ; b, b, the small blind 

 dilatations presented by the lacrymal canalicules, 

 where they bend inwards to the lacrymal sac ; c, c, 

 continuation of the lacrymal canalicules ; d, d, 

 their entrance into the lacrymal sac ; e,f, g, lacry- 

 mal sac ; e, blind end of the lacrymal sac ; f, middle 

 part of the lacrymal sac ; g, its termination ; h, i, 

 nasal duct j i, opening of the nasal duct into the 

 nose. 



margin of each eyelid, where the fissure of the 

 nasal canthus begins, there has been already de- 

 scribed a small papillary eminence, lacrymal 

 papilla, papilla lacrymalis, in the summit of 

 which is a small orifice, lacrymal point, of 

 such a size as to admit a thick bristle. The 

 lacrymal points, puncta lacrymalia; Fr. Les 

 points lacrymaux ; Ital. I punt i lagrimali ; 

 Germ. Die T/iranenpunkten ; are from their 

 size and situation sufficiently conspicuous as not 

 to be confounded with one of the orifices of the 

 Meibomian follicles. In the natural state the 

 lacrymal papillae are inclined towards the lacus 

 lacrymalis. The lower papilla is somewhat more 

 prominent than the upper, and situate some- 

 what more towards the temple. The lacrymal 



canalicules, canaliculi lacrymales, s. cornua 

 limacum; Fr. Les conduits lacrymaux ; Ital. 

 I condotti lagrimali; Germ. Die Thranen- 

 kanalchen ; lead from the lacrymal points into 

 the lacrymal sac. From the superior lacrymal 

 point the superior canalicule proceeds upwards 

 and outwards within the papilla a little way, 

 then suddenly bending at an acute angle and 

 forming at the same time a small dilatation, 

 it runs downwards and inwards, inclosed in 

 the fold of skin and conjunctiva forming the 

 upper border of the fissure of the nasal can- 

 thus, to the lacrymal sac. The course of the 

 inferior canalicule is the counterpart of the 

 above. From the lower point it runs a short 

 way perpendicularly downwards and outwards 

 within the corresponding papilla, then bend- 

 ing abruptly and like the upper forming a 

 small dilatation, it proceeds upwards and in- 

 wards, inclosed in the fold of skin and con- 

 junctiva forming the lower border of the fissure 

 of the nasal canthus, to the lacrymal sac. 



The canalicules having met each other at the 

 commissure of the fissure of the nasal canthus, 

 pass under the tendon of the orbicularis mus- 

 cle, and open by separate orifices, close to each 

 other however, into the anterior and outer part 

 of the lacrymal sac. These orifices indeed are 

 separated merely by a duplicature of the mucous 

 membrane composing their walls. 



The lacrymal canalicules have pretty firm 

 walls of mucous membrane, which do not col- 

 lapse, but when cut across are seen gaping 

 open. The calibre of the canaliculi is about 

 the thirtieth of an inch in diameter ; that of the 

 points is less, but these are capable of being 

 dilated. 



The canaliculi are immediately surrounded 

 by the fibres of the internal palpebral ligament, 

 and those of the tensor tarsi muscle. 



Lacrymal sac ; saccus lacrymalis ; Fr., Le sac 

 lacrymal ; Ital. II sacco lagrimale; Germ., Der 

 Thr'dnensack. (Fig. 16J. This is a membra- 

 neous reservoir of a vertically elongated form, 

 and externally compressed, nine-twentieths of 

 an inch long, and two-tenths broad externally. 



Fig. 16. 



Derivative lacrymal passages of the left side, seen from 

 the side of the nasal cavity. 



Here it is seen that the nasal duct is much 

 broader viewed from the side than from before, a, b, 

 superior and inferior lacrymal canaliculi ; c, d, 

 lacrymal sac ; e, f, nasal duct ; /, nasal orifice of 

 the nasal duct, seen quite in its natural state. 



