APPENDAGES OF THE EYE. 349 



the lenses, and producing a variety of colors, as seen in 

 the solar spectrum, is corrected in the living eye by the 

 presence of different media, each having different density 

 and different refracting power, thus balancing each other, 

 and thereby preventing any confusion arising from color. 



APPENDAGES OF THE EYE. 



The Appendages of the Eye (tutamina oculi) consist of the 

 Muscles, Eyebrows j Eyelids, and Lachrymal Apparatus. 



The Muscles Flo 102t 



belong to the 

 globe of the 

 eye, the upper 

 eyelids and the 

 tar sal cartil- 

 ages. To the 

 globe belong 

 six muscles, 

 four straight 

 and two ob- 

 lique. The straight, called recti, consist of the superior, 

 inferior , external and internal recti. 



Dissection. The rectus superior, or levator oculi, situ- 

 ated beneath the upper eyelid and the levator palpebrarum 

 muscle, is exposed by removing the roof of the orbit, which 

 is done by sawing the frontal bone at the outer and inner 

 extremities of its orbitar edge, when with a few blows by 

 the hammer upon the superciliary portion, it can be re- 

 moved. The brain is supposed to have been first taken 

 away. 



This muscle arises from the superior margin of the optic 

 foramen small and tendinous, also from the fibrous sheath 

 of the optic nerve. It passes forward over this nerve and 

 the superior portion of the ball, and is inserted into the 

 sclerotic by small tendinous fibres near the cornea. 



Fia. 102 represents the Muscles of the Eye-ball, o Optic nerve. 6 Trige- 

 minus or fifth pair of nerves, c Ganglion of the fifth pair or of Gasser. d 

 Superior oblique muscle, e Rectus superior. / Rectus externus. g Rectus 

 inferior, h Obliquus Inferior, i Ball of eye. j Levator palpebrarum. 



