188 THE MENDEL JOURNAL 



then from two apparently healthy people, there may 

 thus be produced some affected offspring. 



The same considerations apply to cataract and 

 to the degeneracies sometimes associated with these 

 abnormalities. They are not simple attributes. They 

 are doubtless characters of a complex nature. Lentil 

 we are able to determine precisely the nature and number 

 of the factors which when present simultaneously in 

 the lens of the eye, produce cataract, we cannot predict 

 the precise mode of descent of the abnormality, nor 

 indicate the percentage of offspring in whom it should 

 be present or absent . But that we have clean segregation 

 of the normal from the abnormal, as shown by Dr. 

 Rutherfurd's observations, is as far as it goes, ver}' good, 

 if incomplete, evidence of Mendelian inheritance. 



The question of " anticipation," as Mr. Nettleship 

 and others have called it, and which Dr. Rutherfurd 

 describes in the paragraph entitled " General Con- 

 siderations," is of great interest and deserves fuller 

 consideration in the light of recent Mendelian research. 

 We do not, however, now propose to further consider it. 



