APPENDIX 3^5 



Expt. 7. The offspring of 28 plants inherited the long axis, and 

 those of 72 plants some the long and some the short axis. 



In each of these experiments a certain number of the plants came 

 constant with the dominant character. For the determination of 

 the proportion in which the separation of the forms with the con- 

 stantly persistent character results, the two first experiments are 

 of especial importance, since in these a larger number of plants can 

 be compared. The ratios 1.93 to 1 and 2.13 to 1 gave together 

 almost exactly the average ratio of 2 to 1. The sixth experiment 

 gave a quite concordant result; in the others the ratio varies more 

 or less, as was only to be expected in view of the smaller numl^er of 

 100 trial plants. Experiment 5, which shows the greatest depar- 

 ture, was repeated, and then, in lieu of the ratio of 60 and 40, tliat 

 of 65 and 35 resulted. The average ratio of 2 to 1 appears, thereforey 

 as fixed with certainty. It is therefore demonstrated that, of those 

 forms which possess the dominant character in the first generation, 

 two-thirds have the hybrid-character, while one-third remains 

 constant with the dominant character. 



The ratio of 3 to 1, in accordance with which the distribution of 

 the dominant and recessive characters results in the first genera- 

 tion, resolves itself therefore in all experiments into the ratio of 

 2:1:1 if the dominant character be differentiated according to its 

 significance as a hybrid-character or as a parental one. Since the 

 members of the first generation [F2] spring directly from the seed 

 of the hybrids [Fi], it 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 the recessive characters 

 [respectively] in equal numbers. 



The Subsequent Generations [bred] from the Hybrids 



The proportions in which the descendants of the hybrids develop 

 and split up in the first and second generations presumably hold 

 good for all subsequent progeny. Experiments 1 and 2 have 

 already been carried through six generations, 3 and 7 through five, 

 and 4, 5, and 6 through four, these experiments being continued 

 from the third generation with a small number of plants, and no 

 departure from the rule has been perceptible. The offspring of the 

 hybrids separated in each generation in the ratio of 2:1:1 into 

 hybrids and constant forms. 



