8 Darbishire, Mendelian Principles of Heredity. 



result on the paper : the outcome of such a trial taken as 

 I write is 13 RR, 26 RW zxi^ 11 WW ; which, for the 

 smallness of the number drawn, is not a bad approxi- 

 mation. Let that colour represent the dominant character, 

 which was placed uppermost in the R W's : let W be the 

 recessive and R W the hybrid : the observance of the only- 

 rule of the game brings out the fact that in the hybrid it 

 is the dominant character which is manifested, while the 

 recessive is hidden. Now, in placing the R W's on the 

 paper one is not likely to absolutely conceal the white ; 

 so that, while from our rule, we realise that red is the 

 character which the hybrid bears, we are prevented (by 

 the fact that the white is not absolutely concealed) from 

 forgetting the real constitution of the hybrids (or rather 

 their gonads) namely that they contain germs representing 

 respectively dominant and recessive characters in equal 

 numbers. It will be seen from this illustration that, 

 in making the living cross, all that is done is 

 to mingle (if this word may be used of two objects) 

 the germ cells together* like counters in a hat ; and that, 

 in the resultant hybrid, the germ cells differ from the two 

 which took part in its formation, only in actual number ; 

 for the proportions are the same (50% dominant and 50% 

 recessive) and the discontinuous condition of the germ 

 cells is the same, in as much as a germ-cell represents 

 either a dominant or a recessive, and never partly one and 

 partly the other ; in fact it is no more possible to produce 

 such an intermediate stage than it is possible to get a 

 pink counter by shaking up scarlet and white ones in a hat. 

 To look for a moment at the offspring of the hybrids ; 

 Mendel says that the " extracted " dominants (the 

 dominant offspring of the hybrids) will always breed true ; 



* Of course the germ cells fuse : it is the character-bearing elements 

 which are thus mingled. 



