Heredity 173 



Compare this carefully with problem 4 with special 

 reference to the actual counts as compared with theo- 

 retical ones. 



The offspring of the hybrids appeared, therefore, under 

 nine different forms, some of them in very unequal num- 

 bers. When these are collected and coordinated, we 

 find:- 



38 plants with the sign RY. 



35 plants with the sign Ry. 



28 plants with the sign rY. 



30 plants with the sign ry. 



65 plants with the sign RYy. 



68 plants with the sign rYY. 



60 plants with the sign RrY. 



76 plants with the sign Rry. 

 138 plants with the sign RrYy. 



The whole of the forms may be classed into three essen- 

 tially different groups. The first includes those with 

 the signs RY (or RRYY, as previously designated it is 

 not necessary, however, to repeat the letters), Ry, rY, and 

 ry ; they possess only constant characters and do not vary 

 again in the next generation. Each of these forms is 

 represented, on the average, thirty-three times. 



The second group includes the signs RYy, RrY, Rry; 

 these are constant in one character and hybrid in another, 

 and vary in the next generation only as regards the 

 hybrid character. Each of these appears, on the average, 

 sixty-five times. The form RrYy occurs 138 times; it 

 is hybrid in both characters and behaves as do the hybrids 

 from which it is derived. 



