1025 



The first concerns the germinating-power of the seed. 



I have repeatedly noticed that (lie seed of white-flowering varieties 

 has a germinating-power inferior to that of the blue ones, i.e. a 

 relatively smaller number of seeds of the former germinate. This 

 difference existed also between the two forms which I crossed. The 

 seed of Egyptian blue tlax, which I used for my cultures, had very 

 good power of germination; almost all its seed came up, as the 

 following figures show. Out of 706 seeds 701 germinated and 

 developed (o plants, thus only 0.71 7o faded. The white-flowering 

 flax, on the other hand, germinated badly and a number of seedlings 

 died at a very early stage. 682 seeds yielded 601 plants, that is a 

 loss of 11.9 7o- Now there are obtained from the 1\ plants and the 

 heterozygous plants of the following generation both seeds producing 

 white-flowering plants and seeds producing blue ones. If then a 

 higher percentage of this seed than of the blue flax does not 

 germinate, then it may safely be assumed that the loss almost entirely 

 arises through the failure of the seeds of the white-flowering plants. 

 I have not traced the proportion between the number of seeds sown 

 and the numl)er of plants obtained for all the cultures of the whole 

 3906 plants to be foun<l in the tal)le, but only for about the half. From 

 these it was found that 1916 seeds yielded 1858 plants. There was 

 therefore for 1858 plants obtained a loss of 58. That will amount 

 to 122 for the 8906 plants reckoning all the cultures together. 

 Since of the 3906 plants 3106 had blue flowers and since we saw 

 that among the blue y-'-form the 701 plants obtained, 5 seeds did 

 not germinate, we may assume that in this case out of the 122 

 seeds which did not germinate, there were 22 which should have 

 given blue-flowering plants and conse(|uently 100 which should have 

 given the white-flowering ones. In this it is assumed that heterozygotes 

 behave as homozygous blues. 1 shall retui-n to this point later. 



Now we may inquire whether the number of 100 thus found is 

 sufficient to explain the whole deficiency of white-flowering plants". 

 3106 blue-flowei'ing plants were observed, to which belong 22 seeds 

 which did not germinate. We may therefore assume, that among 

 the seeds which were sown, there were 3128 of them with a 

 predisposition towards the blue colour of the flower. Theoretically 

 Vs of this nund)er, that is 1042 73» o^" hi round number 1043 

 seeds should have given white-flowering plants. 



Onl}^ 800 are found, however. The deficiency amounts therefore to 

 243. Now we saw that by reason of the inferior germinating- 

 power of the seed 100 white-flowering plants will be wanting. 

 This is, however, much less than the observed deficiency, so much 



67* 



