XC1I 



BOWMAN LECTURE. 



seen, hereditary cataract often occurs at an earlier age in 

 the children than in the parents,* whilst in those of the same 

 generation it frequently begins at about the same age in 

 each. Fuchsf remarks that when senile cataract is a 

 family disease it often comes on unusually early. 



This earlier incidence in each generation " anticipa- 

 tion" is not known to be accompanied by disease or early 

 degeneracy of other parts of the body; but more data are 

 much needed upon this important point. 



Of postponement onset later in the next generation 

 there is next to no evidence in cataract, but ocasionally when 



cataract begins at the same age in near relatives it may 

 progress at very different rates in each of them.t 



* For good published pedigrees showing anticipation see R.L.O.H., 

 xvi, p. 179, et seg., Cases 2, 4, 5, 7, 8, 15, 46 and 390 ; Dr. Green's Case 

 Fig. 18 in present lecture, the numbers on which are from Dr. 

 Green's figure and do not represent ages; R.L.O.H., loc. cit., Cases 

 40, 41 (p. 208) ; a case published in T.O.S., xxviii, p. 220 (present Fig. 

 25) ; another published in T.O./S'., xxix, p. 209 (present Fig. 24, giving 

 some of the ages). Also Figs. 21 (Westly, Mr. Fisher's case) and 23 

 (Helyer, Dr. E. J. Smyth's case) now recorded for the first time, and 

 giving the ages of onset. Figs. 19 (Sichelfils), 20 (Louis Strieker), and 

 22 (unpublished case of my own) all show the same feature and some of 

 the ages are indicated. 



f Fuchs, Text-Book of Ophthalmology. 



t R.L.O.H., xvi, p. 179, et. seq., Case 13. 



