74 



yellow color ; wliile by a partial cataract tlie normal color 

 of the pupil is cut off at the points or places of local opaci- 

 ties of the lens or its capsule. In cloudiness of the vitreous 

 humor the pupil becomes more or less distinctly green. A 

 liquid condition of the vitreous humor combined with cloudi- 

 ness of the same also produces a distinct green pupil. 

 Sudden or great movement of the cloudy vitreous humor, 

 is a certain proof of its fluidity. The observer should view 

 the pupil from various positions; by the use of the hand or 

 a black hat the superfluous rays of light, or those coming 

 from certain directions, may be cut off. The observer 

 should not mistake the images of white objects (white shirt 

 fronts, windows, holes in the building), for white or gray 

 opacities in the lens or other parts of the eye. 



Dislocation of the lens, falling of the opaque lens into the 

 anterior or aqueous chamber of the eje has its appearance 

 suggested by figure 13. But if the opaque lens should fall 

 into the vitreous humor, the upper jiart of the pupil may 

 remain transparent, and the small appearing optic papilla 

 might be visible ; yet a portion of the white or gray opaque 

 lens could be seen through the lower j)art of the pupil ; as a 

 rule, the iris remains passively inactive and its pupillary 

 border floats in the aqueous humor. Sometimes the lens 

 may be partially dislocated or may have some shred-like, or 

 hanging thread-like, attachments to its old location ; these 

 conditions would present different views in the jjupil. 



In order to be more accurate in locating and discovering 

 opacities, the animal should be placed in a dark room where 

 the eye may be illuminated by the use of a lamp or candle. 

 The lamp may be placed in different locations, in front of, 

 and outward from, the eye to be inspected ; opacities will 

 then be made more distinct. Three images of the flame 

 may be seen as illustrated in figure 18. In the normal eye 

 the first image is the largest, upright, the most distinct and 

 reflected from the front surface of the cornea; the second 

 image is smaller, upright and reflected from the anterior 

 surface of the lens ; the third one is the smallest, inverted 



