NERVUS TRIGEMINUS. 457 



fra-orbitary. According to Dr. G. Transmondi,* of Rome, two 

 filaments may be traced very distinctly from the external na- 

 sal nerve to the tensor tarsi muscle of the lachrymal sac. They 

 adhere to the muscle by means of cellular structure, and pass 

 on to its bifurcated extremities and to the puncta lachr^ma- 

 lia. 



The Frontal Nerve is the largest of the three branches of 

 the ophthalmic. It proceeds forward between the levator pal- 

 pebrae superioris and the contiguous part of the orbit, and in 

 this course is divided into two branches, the internal and the 

 external frontal nerve. .The former approaches the trochlea 

 of the upper oblique muscle, and detaches a filament to join 

 with one from the Nasal nerve. Other filaments are detached 

 to the upper eyelid, some of which anastomo.-e with filaments 

 from the Lachrymal nerve. The internal branch of the frontal 

 then issues from the orbit just by the trochlea, and, in ascend- 

 ing, is lost upon the occipito-frontalis, the corrugator super- 

 cilii, and the orbicularis muscle. The external branch of the 

 frontal issues from the orbit, through the supra-orbitary fora- 

 men. It quickly detaches a filament, which goes outwardly to 

 anastomose with the facial; the remaining part of the nerve is 

 distributed to the occipito-frontalis, to the corrugator supercilii, 

 to the integuments of the forehead, and to the scalp. This dis- 

 tribution, according to Bichat, is best followed by detaching the 

 skin, muscles, and periosteum from the cranium, from behind 

 forwards as far as the orbit. 



The Lachrymal Branch of the ophthalmic nerve goes for- 

 wards along the external side of the orbit near the superior 

 margin of the rectus externus muscle. In this course it sends 

 off a filament through the spheno- maxillary fissure which unites 

 with one from the second branch of the fifth pair; it afterwards 

 sends off another filament, which, passing through a foramen 

 in the malar bone, anastomoses with a filament of the facial 

 nerve. What remains of the lachrymal nerve is then distri- 



* Intorno la scopcrta di due nervi del Occhio umano ragguaglio del Dr. Giu- 

 seppe Trasmondi, Professore di Anatomia Practica nel ven. ospidale della Con- 

 solazione. Roma, 1823. 

 VOL. If. 40 



