BOWMAN- LECTURE. CXXVII 



series mentioned above,- being about fifty-five males to 

 forty-five females."* 



In the small series available (-ten families) consanguinity 

 has not been recorded in any, but I am not sure that 

 inquiry was always rnade ; and even if it had been we could 

 not attach importance to tji^.a^sence of consanguinity in 

 so small a number. In general albinism consanguinity of 

 parents is common. This '-fact together with the very 

 great frequency of discontinuous; descent in human albinism 

 point to its being a MeAdelian "recessive. But apart from 

 the question of correct numerical proportions, the infinite 

 varieties both of degree and distribution of albinism in man, 

 i. e. the frequency of intermediates, appears to militate 

 against the applicability of the theory. This leads to the 

 remark that in speaking of albinism we need a definition, 

 and, without going into controversial matters with which, 

 in the present case, I am not fitted to deal, I may at once 

 say that, whatever may be true for such of the lower 

 animals as have been fully examined, it is quite clear that 

 for man we cannot limit the term to persons whose skin, 

 hair and eye tissues are perfectly devoid of pigment. Jn 

 the first, or last, place you cannot tell without micros- 

 copical examination whether a given skin or hair or eye 

 contains a little pigment in certain places or none at all 

 anywhere ; and therefore if we refuse the term " albinism " 

 when any trace of pigment is present we must refuse to 

 diagnose albinism in man at all until someone has examined 

 a human eye thoroughly and found it absolutely free from 

 pigment. So far as I know this has not yet been done 

 not because such eyes do not exist, but because in them- 

 selves they are rare and the opportunity of getting them 

 for anatomical examination enormously more so. Clinically 

 we all know that every degree of defective pigmentation 

 occurs in skin or hair or eyes, or in all together, to which 

 we cannot refuse the term " albinism," qualified when 



* In upwards of 1000 albinos of all races and various degrees, the 

 excess of males is found not only in the aggregate, but in each separate 

 group used in the summation. 



