J20 TRANSMISSION 



the proportion of 3 to I . The number of the hybrids as compared 

 with the constants was therefore 1.93 to i. In Experiment 2 it 

 was 2.13 to i ; in Experiments 3-7 the numbers were small, but 

 approximated the same ratio. 



From this Mendel states the following conclusion regarding 

 the offspring of hybrids l (italics his) : 



// is now clear that the hybrids form seeds having one or other of the two 

 differentiating characters, and of these one half develop again the hybrid 

 form, while the other half yield plants which remain constant and receive 

 the dominant or recessive characters (respectively) in equal numbers. 



This conclusion, which seems to be in accord with his results, 

 is clearly against the possibility of effecting a real cross between 

 characters that behave as do those in question. 



Subsequent generations. On this point Mendel says : 2 



The proportion in which the descendants of the hybrids develop and split 

 up in the first and second generations presumably holds good for all subse- 

 quent generations. Experiments i and 2 have already been carried through 

 six generations, 3 and 7 through five, and 4, 5, and 6 through four . . . 

 and no departure from the rule has been perceptible. The offspring of the 

 hybrids separated in each generation, in the ratio of 2 : i : i, into hybrids 

 and constant forms. 



That is to say, of the offspring of hybrids one fourth resembled 

 one pure parent and ever afterward bred true with respect to the 

 character in question; one fourth resembled the other and also 

 bred true ; and one half still remained hybrid, but its offspring, 

 in its turn, fell apart after the same ratio i : 2 : i. 



When more than two characters are involved. Mendel con- 

 ducted investigations with plants differing in a number of char- 

 acters simultaneously and concludes as follows : 3 



That the offspring of the hybrids in which several essentially different 

 characters are combined represent the terms of a series of combinations in 

 which the developmental series for each pair of differentiating characters are 

 associated. It is demonstrated at the same time that the relation of each pair 

 of different characters in hybrid union is independent of the other differences 

 in the two original parental stocks. 



If ^represents the number of the differentiating characters in the true 

 original stocks, 3" gives the number of terms of the combination series, 4" 



1 Bateson, Mendel's Principles of Heredity, p. 57. 



2 Ibid. p. 57. 3 Ibid. pp. 64-65. 



