122 MENDELISM CHAP. 



lady who had married a white man. Some of the 

 children were intermediate in colour, but two were 

 fair whites and two were dark as dark Hindus. 

 This sharp segregation or splitting out of blacks and 

 whites in addition to intermediates strongly suggests 

 that the nature of the inheritance is Mendelian, 

 though it may be complicated by the existence of 

 several factors which may also react upon one 

 another. Nor must it be forgotten that in so far as 

 these different factors are concerned the whites them- 

 selves may differ in constitution without showing 

 any trace of it in their appearance. Before the case 

 can be regarded as settled all these different 

 possibilities will have to be definitely tested. With 

 the dark Eastern races as with the negro we cannot 

 hope to come to any conclusion until we have 

 evidence collected by critical and competent 

 observers. 



Though for the present we must regard the case 

 of the negro as not proven, there are nevertheless 

 two others in which the heredity would appear not 

 to follow the Mendelian rule. Castle in America 

 crossed the lop-eared rabbit with the normal form, 

 and found that the F a animals were intermediate 

 with respect to their ears. And subsequent experi- 

 ment showed that, on the whole, they bred true to 

 this intermediate condition. The other case relates 

 to Lepidoptera. The speckled wood butterfly 

 (Pararge egeria) has a southern form which differs 

 from the northern one in the greater brightness and 

 depth of its yellow-brown markings. The northern 

 form is generally distinguished as var. egeriades. 

 Bateson crossed the southern form from the south 



