Principles of Heredity 203 



cases of " flaked " or " bizarre " unions of bright colours 

 and white which reproduce themselves by seed with fair 

 constancy, though Mendelian purity in respect of these 

 colours is elsewhere common in the varieties (I suspect 

 mosaics of " false hybridism " among allelomorphs in some 

 of these cases). Similarly Galton has shown that though 

 children having one light-eyed and one dark-eyed parent 

 generally have eyes either light or dark, the comparatively 

 rare medium eye-coloured persons when they mate together 

 frequently produce children with medium eye-colour. 



In this connection it may be worth while to allude to a 

 point of some practical consequence. We know that when 

 pure dominant say yellow is crossed with pure recessive 

 say green the dominance of yellow is seen ; and we 

 have every reason to believe this rule generally (not 

 universally) true for pure varieties of peas. But we notice 

 that in the case of a form like the pea, depending on 

 human selection for its existence, it might be possible in 

 a few years for the races with pure seed characters to be 

 practically supplanted by the "mosaicized" races like the 

 Telephone group, if the market found in these latter some 

 specially serviceable quality. In the maincrop peas I 

 suspect this very process is taking place*. After such a 



* Another practical point of the same nature arises from the great 

 variability which these peas manifest in plant- as well as seed- 

 characters. Mr Hurst of Burbage tells me that in e.g. William the 

 First, a pea very variable in seed-characters also, tall plants may be 

 so common that they have to be rogued out even when the variety is 

 grown for the vegetable market, and that the same is true of several 

 such varieties. It seems by no means improbable that it is by such 

 roguing that the unstable mosaic or blend-form is preserved. In a 

 thoroughly stable variety such as Ne Plus Ultra roguing is hardly 

 necessary even for the seed-market. 



Mr N. N. Sherwood in his useful account of the origin and races 



