The Mendelian Inheritance of Certain Chemical Characters in Maize. jn 



Kernels of the type FFSS have a percentage fat content of 4.28 



„ ,, ,, ,, ÖSS ,, „ ,, „ „ ,, 9.02 



„ „ „ FfSs „ „ „ „ „ „ 4.74 



These are all of the gametic constitutions for which we know the 

 actual content of the kernels by direct analysis. We must accordingly 

 make assumptions as to the fat content of kernels of other consti- 

 tutions, being guided, of course, in these assumptions by what we 

 actually know. The basic assumption made in what follows is that 

 ss tends to inhibit or prevent the expression of F. SS luis no 

 such effect on i. In detail this assumption works out as follows: 



In the presence of ss an Ff kernel is assumed to be like an it 

 kernel in fat content (i. e., like the pure sweet parent). 



In tlie presence of ss an FF kernel is assumed to have its fat 

 content reduced to a point half-way between that of the pure dent 

 and pure sweet parents. 



These are the only assumptions made which involve any departure 

 from the results of the direct analyses of the P and Fj kernels. Thus 

 in the calculations which follow any kernel bearing FF is taken to 

 have the fat content of the pure dent parent (4.28 %) except it also 

 carries ss; any kernel bearing Ff is taken to have the fat content of 

 the Fj progeny except it also carries ss; and finally any kernel 

 bearing ff is taken to have the fat content of the pure sweet parent 

 in every case. 



Let us proceed to the calculation of the expected content of the 

 F2 kernels in crude fat on the basis so far developed. Taking first 

 the starchy Fo kernels, we have seen that none of these, either 

 yellow or white, carries ss. Therefore we should expect to find in a 

 random sample of either yellow or white starchy Fg kernels the follow- 

 ing relations as to fat content: 



I FF = 4.28 



1 ff = 9.02 



2 Ff = 2 X 4.74 = 9.48 



Sum = 22.78 



22 78 

 Whence — --= 5.695 = expected percentage of crude fat 



in F2 starchy kernels. 



But 5.32 = mean observed percentage of crude 



fat in all Fo starchy kernels (yellow 



obs. = 5.03, white obs. - 5.61). 



