CONFORMITY TO TYPE 



269 



The disposition of these characters traceable from 

 either parent into the hybrid shows that each hybrid 

 is not, so to speak, composited of two factors, but 

 compounded of many units, which must occur as such 

 in the germ plasm. To such of these units as are 

 found to undergo segregation in the germ plasm of the 



B 



DBBB CZZHR 

 PI * I IR 



Rat ID: i R 



atlD 



FIG. 101. Schema of Mendel's law for a single pair of "antagonistic" proper, 

 ties: A, The results of hybridization of a pure dominant (D) with a pure 

 recessive (R) form; B, the results of crossing a hybrid with a recessive form 

 (50 per cent, of progeny pure recessive, 50 per cent, hybrid but apparently 

 dominant) ; C, the result of crossing a hybrid with a dominant form, all apparenty 

 dominant (but 50 per cent, pure, 50 hybrid). (Bateson.) (P) signifies the parental 

 combination; FI and F 2 , the first and second filial combinations. 



hybrid, and consequent separation in its offspring, Bateson 

 has given the name Allelomorphs. The allelomorphic 

 units are found to go in pairs, the individuals being 

 separable and therefore capable of varying combinations. 

 Germinal cells in which the allelomorphic units are of 

 the same kind are said to be homozygous; those in which 

 they are of opposed kinds, heterozygous. 



