THE SENSES 



$59 



Fig. 177. — The Cardinal Points of the Eye of the Horse (Berlin). 



F, is the first principal focus, situate 1838 ram. in front of the cornea. 

 C is the anterior principal point. 



H, is the first principal point, distant from the cornea 8*13 mm. 

 H„ is the second principal point „ „ „ 9*28 mm. 



K, is the first nodal point „ „ „ 17-03 mm. 



K„ is the second nodal point „ „ „ 18-18 mm. 



K„ to a is the distance of the retina from the second nodal point, 25-32 mm. 

 C to F„ is the distance from the cornea to the second principal focus (which Berlin 

 shows to be behind the retina), 44-69 mm. 



Fig. 178. — The Cardinal Points of the Reduced Eye of the Horse 



(Berlin). 



through the nodal point n without undergoing refraction, while 

 the rays be and Vc' are refracted to a greater or less extent, so 

 that in this way the retinal image becomes inverted, and very 



