204 



DETAILED SYNTHESIS. 



with a large one, called a sac, the lower end of which 

 leads into the lower part of the nose. (See PL 4.) 



818. It is not unusual for A COLD transiently or per- 

 manently to stop the ducts leading from the eye. Pressure 

 upon the upper part of the sac will sometimes clear the 

 passages again. If they are permanently closed, a small 

 silver tube can be inserted, that will draw the fluid off 

 from the eye and prevent its overrunning, and obviate 

 the attendant wiping, that is likely to injure the eye. 

 FIG. 200. 



Fig. 200 exhibits a magnified section of the eye. a, the lashes of b, the 

 upper, d, the under lid, in the middle of which the orbicularis is to be 

 seen, and in the back part the Meibomian glands opening at the edges of 

 the lids ; c, the upper and lower points of the lining of the inside of the 

 lids ; i, the cornea ; d, the sclerotic ; k, the choroid ; ,;, its division ; k, 

 ciliary ligaments, b, body, /, muscle; m, iris; v, anterior chamber; , 

 posterior chamber; t t lens; o, retina; r, central artery; p, hyaloid; , 

 vitreous humor; e, muscle raising lid; f, superior rectus; g, inferior rec- 

 tus ; y, fat. 



818. What frequently the effort of ? What docs Fi#. 200 represent? Class 

 the parts of the eye represented under thrir proper heads. 



