HEREDITY. 75 



only recessives. When those like the dominant grand- 

 parent are in-bred, some yield pure dominants only that 

 is, forms which if in-bred yield only dominants ; but others 

 yield apparent dominants like the original hybrid that is, 

 with the power of throwing off when in-bred more pure 

 dominants, more pure recessives, and more apparent 

 dominants like the original hybrid. The results tend to 

 be always in the proportion iA+2A (B) + iB, as regards 

 the two contrasted characters of A and B. 



Two diagrams (after T. H. Morgan and R. C. Punnett) 

 may make the matter clearer. 



A (B) 



I A 2 A (B) i B 



A i A 2 A (B) i B B 



A A 



D(R) 



