62 THE BOTANICAL MAGAZINE. LVoi. xxxiv No. 401. 



The White single is a homozygote ccRRdd so the gamates from 

 the latter will be cRd ; the Magenta double is a heterozygote CcRrDd, 

 the gamates will be CRD, CRd, CrD, Crd, cRD, cRd, crU, erd. Thus 

 the Z} r gotes from the two sets of gamates mated will be, CRD : CRd : 

 CrD : Crd : cRD : cRd : crD : crd x cRd = 1 CcRRDd (magenta double) : 1 

 CcRRdd (magenta single) : 1 CcRrDd (magenta double) : 1 CcRrdd 

 (magenta single) : 1 ccRRDd (white double) ; 1 ccRRdd (white single) : 

 1 ccRrDd (white double) : 1 ccRrdd (white single) = 1 magenta double: 

 1 magenta single : 1 white double : 1 white single. 



Experiment 2. Pale yellow single CCrrdd X White double. The 

 result is given in the table 7. 



Table 7. 



Magenta Magenta Yellow Yellow 



single double single double Total 



Pedigree No. 106 4 15 4 5 28 



„ 111 15 10 8 4 37 



113 9 17 9 5 40 



115 9 15 6 15 45 



116 6 3 2 3 14 



Act. observ 43 60 29 32 164 



Theor. expect, as 1: 1. : 1: 1. 41 41 41 41 164 



Deviation +2 +19 -12 -9 



r/labs ±5.5 ±5.5 ±5.5 ±5.5 



Deviat/Wabs 0.36 3.42 2.16 1.62 



The result obtained here differs from that of the experiment B 

 by the fact that here we have yellows in addition to magentas. A 

 little excess of the magenta double may be explained by the assump- 

 tion that the individuals of the other classes were weaker than those 

 of the magenta double class, so that some of the former did not 

 come into development. 



The result in the table 7 is interpreted as follows : 



The pale yellow is homozygote, therefore the gamates produced 

 are of one kind Crd. The white double is a heterozygote as will be 

 seen from its pedigree given" here. 



The pedigree of the white double : 



1916. A scarlet single mated with a white double race No. 1. 

 produced seeds. 



1917. The pure white single ccRRdd, i.e. experiment B. 1, P. 

 white single, was pollinated with the pollen from the magenta double, 

 which was raised from the seeds of 1916. 



