392 Origin of Each Species Considered Separately. 



the proportions for the other mutants seem to have been 

 inverted. 



This result tends to prove the correctness of the 

 conclusion, suggested above (p. 389), that the devia- 

 tions from the mean hereditary coefficient are phenom- 

 ena of fluctuating variability and have nothing to do with 

 mutation. 



The fifth mutant of O. scinfillans from which I was 

 able to get seed arose in 1898 from the /a/a-family de- 

 scribed on page 285. There was only one plant which 

 unlike all the previous ones developed a stem very early 

 and flowered in the first summer. It was self-fertilized 

 in a bag, set little seed and gave rise in 1899 to 148 

 identifiable plants of which 37 % were scintillans^ 



This is another example of the hereditary coefficient 

 exhibited bv two of the three other mutants which were 

 tested — a particularly interesting case because the origin 

 of this scintiUans was quite different from that of the 

 others and the plant was an annual. 



I shall now summarize these coefficients. 



SOURCE YEAR OF MUTATION 



SCINTILLANS PLANTS 



2nd gen. 3rd gen. 4th gen. 



O. lata 1888 — IS % 

 O. lata 1898 37 % 



O. Lamarckiana 1895 34—36 % 40 % 

 O. Lamarckiana 1896 39 % 



O. Lamarckiana 1896 69 % 84 % 79 % 



These figures seem to be arranged in groups of 15 %, 

 34-40 %, and 69-84 %. It would obviously be very im- 

 portant to determine more of these figures in the case 

 of a large number of ^cm////a/w-mutants ; if this were 

 done the groups will probably turn out to be more vari- 



^ See the first table on p. 245. 



