ix the tropics: in. 135 



T.I.— AN ANALYSIS OF THE METHOD OF INHERI- 

 TANCE OF CERTAIN COLOUR CHARACTERS 

 IN THE CASE OF A MONGREL 

 STRAIN. 



The material for the following experiments consisted of 

 a few specimens of the common kind of corn grown locally — 

 a flint variety in which the colours yellow, blue, red, and white 

 were to be found mingled together in great confusion. Yellow, 

 blue, and white grains were often seen on the same cob, whilst 

 on certain plants all the grains showed the red pericarp charac- 

 ter in addition. 



As will presently appear, it was possible to show that the 

 pair of characters yellow — white behave in a simple Mendelian 

 way. The presence or absence of red in the pericarp behaves 

 in a similar manner. The blue-non-blue was found to behave 

 in essentially the same way as was the case with the definite 

 crosses already described, but here again the mass methods 

 of pollination employed were inadequate to elucidate the 

 phenomena completely. 



Among the cobs of unknown parentage first obtained, the 

 grains (endosperms) of which were regarded as the parental 

 generation (P), were the following : — 



No. 1 bore the following grains : yellow 415, white 224, and 

 blue 118, total 757 ; only the non-blue grains being distin- 

 guished into whites and yellows. The pericarp was trans- 

 parent and colourless (white). 



No. 5. Dark red pericarp. 10 grains near the base of the 

 cob showed a blue colouration, whilst the remainder — some 

 500— were yellow or white, the colour of the endosperm being 

 externally indistinguishable. 



All the different kinds of grain mentioned, from both the 

 above cobs, were sown in small patches which lay close together, 

 and in the neighbourhood of plots sown with grains from other 

 cobs. A large majority of all the grains sown was white, 

 and all were of the same flint form. The intention was to 

 make artificial pollinations, and a considerable number were 



9(8)06 (6, 



