[64 LOCK : STUDIES IN PLANT BREEDING 



The red < olour is thus an ordinary Mendelian dominant ; 

 red and white are heterodynamous and sehizogonous as 

 (Wrens supposed in 1902, although the complete proof was 

 then lacking. The intensity of the red colour varies however 

 considerably from plant to plant, and it was not found possible 

 to rear any certain extracted dominant for comparison. 



B.— COMBINATIONS OF CHARACTERS. 



The same remarks apply here as were given in Part I. 

 under the same heading ; the red, blue, and yellow allelo- 

 morphs appeared to segregate each from its corresponding 

 allelomorph (absence of colour) in complete independence 

 of the other pairs. In the following example, which shows a 

 similar complexity in respect of the supposed yellow- white 

 pair as did the complex cross described in the previous pari , 

 the starch-sugar pair is concerned as well as both pairs of 

 endosperm colour characters. 



Ft. 



Expt. 73. — A plant arising from a heterozygote grain, 

 yellow x white flint, was crossed with pollen from Black Mex- 

 ican sugar corn. There resulted nearly equal numbers of 

 yellow, white, blackish yellow, and blackish white grains, the 

 two last kinds showing a mottled pattern of bluish black over- 

 lying the ground colour. 



The offspring of only the blackish yellow grains (heterozy- 

 gotes presumably in all three pairs of allelomorphs concerned) 

 were examined in detail. 



F2. 



22 plants were obtained from t lie blackish yellow grains, 

 and these were allowed to mutually pollinate one another. 

 The total number of starchy (flint) and sugary grains was 

 given in Table 2 without distinction of colours. In Table 47 

 all the different kinds of grains obtained are enumerated 

 irately. Grains with a blue (or blackish) aleurone layer 

 may oi course be either yellow or white in general endosperm 

 colour, and when the blue colouration was faint, as it was in a 



