SKIN COLOUR 175 



looked for and carefully noted. Particularly should it 

 be noted whether the colour of this offspring is a yellow- 

 brown, intermediate between the two parents, or inclining 

 more to one parent than another, or whether it is a new 

 colour, unlike that of either parent. A further feature 

 of some considerable interest is whether any sambo, 

 known from his parentage to be a sambo, and not merely 

 judged as such by his colour, ever resembles some mulat- 

 toes, or vice versa, whether some mulattoes ever resemble 

 some samboes. There is some reason to believe that this 

 may, now and then, be the case. In general, what is 

 desired, is a very careful and very detailed observation of 

 separate families of all kinds, and not of classes of hybrids. 

 The fuller the pedigree and the farther back it goes, the 

 more valuable it is. But even fragments of pedigrees 

 are of value. All kinds of pedigrees are required, and not 

 only those relating to mulattoes, but to all the various 

 crosses between the pure forms and the hybrids, which 

 are possible. 



A review then of Professor Pearson's evidence shakes 

 our time honoured belief in the existence of the process 

 of blending in the hereditary transmission of the skin 

 colour of the various hybrids resulting from European 

 and negro crosses. The facts are not altogether in accord 

 with what we should expect if gametic blending was 

 operating in these cases. We may therefore next con- 

 sider whether expectations based on segregation any 

 better fit the facts. 



Now there are two possibihties arising from segrega- 

 tion. If the blackness of the negro is an elemental 

 matter, if it is simply blackness and nothing more, and 

 if the colourlessness of the European is merely absence of 

 negro colour, and if the colour factors, whatever they may 

 be, are of the samegenetic nature in Europeansand negroes, 

 then the expectations will be those ascribed to the 

 " theorists " by Professor Pearson. But there is no 

 Mendelian who believes that this is probably the case. 

 Not only does our knowledge of colour inheritance in 

 animals and plants forbid us to believe that it is in Man 

 of any such elementary nature, but anthropological 

 knowledge of quite long standing would similarly prevent 

 us from falhng into such a pitfall. Almost every coloured 



