CTI 



BOWMAN LECTURE. 



HEREDITARY NIGHT-BLINDNESS. 



(Figs. 40 to 43 in text ; 44 in Appendix F.) 



Two sorts of hereditary night-blindness are met with 

 which may be conveniently taken next, although they are, 

 so far as we can tell, absolutely distinct from retinitis 

 pigmentosa, and probably also from each other. * Both 

 are, so far as can be ascertained, present from birth, 

 stationary, and not associated with any other defects or 

 degeneracies. In one of them the defect (it seems hardly 



right to say disease) affects both sexes almost equally, 

 descends continuously through either parent, and is not 

 connected with any other peculiarity of the eyes or sight, 

 nor with any unnatural appearances at the fundus. 

 Besides the now well-known genealogy originally published 

 by Cunier, there are only about half a dozen recorded 

 pedigrees of this abnormality (Figs. 40 and 41 show two of 

 them). Probably, however, the condition is less rare than 

 * A list of the cases, and the pedigrees of some of them given in 

 Appendices I, o and H, and V. 



