C. J. Bond 121 



iris and choroid pigment, has been broken up by the appearance in later 

 years of a dominant character, e.g. hair pigment in the hair of the scalp 

 though not in the hair of the face. 



Bateson also refers to the existence of similar abnormal cases of 

 albinism in man, pp. 226-7. See also Pearson, Nettleship and Usher, 

 On Albinism in Man. 



In one sense this unusual development of a later epistatic character 

 in an albino is only what happens normally in the case of other 

 characters in the young of animals and of human beings. 



All children, with few exceptions, are bom with simplex or blue eyes, 

 the epistatic duplex character only begins to appear from 4 to 8 or 10 

 weeks after birth. 



The same is true of kittens and the young of other animals, while 

 in young pigeons hatched with " bull " eyes the red or yellow anterior 

 pigment begins to be deposited 6 or 8 weeks after hatching. 



In fact following the law of recapitulative ontological development 

 with the addition of characters, epistatic characters seem usually to 

 follow and not precede recessive characters in the process of the 

 unfolding of unit characters in the zygote. 



Hair Pattern in Man. 



But although as we have seen the self-skin colour seems in the case 

 of man at present to resist influences of a genetic kind calculated 

 to break it up into subordinate factors (a state of things tvhich may 

 account for the fact that, when in the human species irregular or parti- 

 coloured iris pigmentation occurs a like particulate distribution of skin 

 colour pattern does not usually occur along with it, at any rate in 

 European races), yet there are some facts which suggest that the 

 factors which control hair structure and its distribution in the human 

 subject are subject to similar disturbances to those which affect the 

 factor for iris pigmentation. 



As a general rule the corkscrew (ellipsoidal sectioned) black hair 

 of the negro is dominant over the wavy (oval sectioned) brown hair of 

 the European. 



And in the majority of the Fi hybrids of the negro and white cross 

 this dominance extends over the whole of the scalp area to all the hair 

 of the head. (Plate IX, fig. 2.) 



In two children L. M. and B. M. out of a family of nine the Fi 

 offspring of an English woman with straight brown hair and a West 

 African negro (Plate VIII) some segregation of the corkscrew and 



9—3 



