HEREDITY 519 



not maintained in each individual plant. As to whether this 

 comes from difficulties in identifying and classifying doubtful 

 specimens, or from some biological reason, Mendel does not 

 express an opinion, though the point is important. 



In other experiments the ratio between the dominants and 

 the recessives was in all cases approximately 3 to i. In Experi- 

 ment 3 (as to color of seed coats), it was 3.15 to I ; in Experi- 

 ment 4 (as to form of pods), it was 2.95 to i ; in Experiment 5 

 (as to color of unripe pods), it was 2.82 to i ; in Experiment 



6 (as to position of flowers), it was 3. 14 to i ; and in Experiment 



7 (as to length of stem), it was 2.84 to i, but the numbers were 

 relatively small (787 and 277) as compared with the numbers 

 involved in Experiments i and 2. 



The third generation, second from hybrids. According to 

 Mendel, 1 " those forms which in the first generation maintain 

 the recessive character do not further vary in the second genera- 

 tion as regards this character ; they remain constant in their 

 offspring. 



" It is otherwise with those which possess the dominant 

 character in the first generation (bred from hybrids). 2 Of 

 these, two thirds yield offspring which display the dominant and 

 recessive characters in the proportion of 3 to i, and thereby 

 show exactly the same ratio as the hybrid forms, while only one 

 third remains with the dominant character constant." That is 

 to say, of the 75 per cent apparent dominants, one third, or 25 per 

 cent, of the whole breeds pure dominants, showing that this 

 proportion is actually what it appears to be, namely, pure domi- 

 nants, while two thirds, or 50 per cent of the whole, yield both 

 dominants and recessives in proportion of 3 to i, showing their 

 essentially hybrid or crossed nature, and that their dominance 

 is apparent rather than actual. The separate experiments yielded 

 ratios as follows : 3 



In Experiment i, among 565 plants raised from round seed 

 193 yielded round seeds only, and remained therefore constant 

 in this character, while 372 gave both round and angular seeds in 



1 Bateson, Mendel's Principles of Heredity, p. 55. 



2 That is, with the 75 per cent apparently dominant. 



3 Bateson, Mendel's Principles of Heredity, pp. 55-58. 



