168 THE MENDEL JOURNAL 



to place such a case on record, so that the details may be 

 accessible to workers in the comparatively new field of 

 experimental heredity. 



In the family here recorded (using the word famil}' in 

 its colloquial and more restricted sense) lenticular cataract 

 occurred in childhood or adolescence in five out of twelve 

 persons (C, 15-26). Another member of the family died 

 many years ago while still an infant, and as naturally no 

 information is available as to him, he cannot be included 

 in the present calculation. Of the five affected members 

 of this family in generation C, I" examined the eyes of two. 

 In addition I examined the eyes of the two affected 

 parents in generation B. Of the six living unaffected 

 individuals I was able to examine five at one time or 

 another. A seventh member died at the age of twenty- 

 four years. The presence or absence of the defect in the 

 persons I was able to examine may therefore be 

 taken as definitely settled. All members so examined 

 will be found indicated in the explanatory description 

 attached to the chart. Three of the affected individuals 

 (Nos. 18, 19, and 21, generation C) in this family were 

 married and had children, the offspring, ten in number, 

 being aged from about seven years to twenty. One of these, 

 No. 15, D generation, as will be seen later, seems to have 

 inherited the affection under consideration. Five of the 

 unaffected members of the family group are married. 

 One has no family ; the children of the others, twelve in 

 number and aged from a twelvemonth to twenty-two 

 years, seem all to have escaped the condition up to the 

 time when these details were gathered. 



An investigation into the family histories of the parents 

 of these five affected persons (C generation) revealed 

 very little. In the mother the cataract had apparently 

 arisen de novo.* The father seemed definitel}^ to owe 

 the origin of his condition to the ancestral germ-plasm, 

 as, although his own immediate parent M^as unaffected, 

 the somatic stigma had displayed itself in one of the 

 members of that generation. The nine cases in the four 

 generations are briefly described below. 



* See Editorial note, p. 184. 



