CLXXXVI BOWMAN LECTURE. 



No information about the ascendants of Gen. I. I, 1 to 7, five 

 brothers, of whom three were affected, and two sisters, both of whom 

 married and had children ; one of them (I, 3) carried the disease, 

 the other (I, 6), had only daughters, and therefore the point could not be 

 determined. II, 4 to 12, nine children of I, 3, six male, of whom three 

 are affected, three female of whom one (II, 8) died at 2 ; one of the sur- 

 vivors (II, 7) carries the disease, and the other (II, 6) has children of 

 both sexes, none of whom have suffered hitherto (but their ages not 



stated). II, 11 and 12, twins, died at three months ; III, 4 still-born; 



III, 5 set. 14 years, affected ; III, 6, 7, 8 have not reached the usually 

 vulnerable age. 



(b) References to Cases of Leber's Disease Illustrating Various Statements 

 in the Lecture. 



Eecovery or marked improvement of sight is to be found in affected 

 members of the following pedigrees : 77 ; one of either 83, 84, or 85 ; 87, 

 93, 49, 115, 116, 122, 132, 136, 141, 144, 160, 170, 171, 172; and in a few 

 others. 



"Anticipation" in Leber's Disease. 



(i) In successive generations, the phenomenon is well shown in the 

 following cases : 80, 49, 96, 108, 111, 112, 113, 50, 153, 154, 51, 168, 174. 



Case 112, Despagnet, shows the anticipation in three generations, and 

 in the case occurring in the third generation one eye recovered whilst 

 the other passed into atrophy of the optic nerve. 



(ii) Anticipation in successively born siblings, and occasionally in suc- 

 cessive sibships of first cousins : 81, 88, 89, 91, 93,49, 98, 99, 102, 105, 110, 

 45, 116, 117, 46, 132, 140, 144, 147, 113, 123, 181a, 150, 48, 156, 159, 171, 

 172, 175. 



Transmission by Affected Males. 



In six pedigrees containing only male cases of the disease 13 of the 

 affected men became fathers, and had from 48 to 56 children, not one 

 of which suffered from the disease, viz., 45 omitting Gens. I and II, 120, 

 47, 168, 174, 167. 



In five pedigrees containing cases of the disease in both males and 

 females, 10 affected men became fathers and had 44 children, of whom 

 4 <$ and 2 ? , six in all, had the disease, viz., 93, 49, 108, 142, 50. 



Adding the two series together we have 23 affected males, who had 

 between them from 92 to 100 children, of whom only 6 became affected, 

 and these six occurred exclusively in pedigrees containing some affected 

 females as well as males. 



Condition of the Parents of Affected Females. 



Both parents normal : 77, 78, 49, 95, 99, 105, 106, 112, 116, 119, 120, 141, 

 123. Father affected, 50 and 93 IV, 1 ; mother affected, 93 and 49. 



