126 Experiments with Primula sinensis 



In Experiments 66/10 and 68/10 the distribution is normal, but in 

 Nos. 67/10 and 79/10, where we expect equality of all four classes, the 

 two middle classes are much larger than the end terms, and though the 

 total numbers are small, the divergence is such that it can scarcely be 

 dismissed as fortuitous. 



The relative sizes of the four classes in the families Nos. 67/10 

 and 79/10, indicate that any repulsion which may take place must be 

 of a low order. The family of 67/10 was raised from seeds obtained 

 from two capsules; but in Experiment 79/10, pollen was taken from 

 only one flower, so that the low type of repulsion indicated by the 

 constitution of that family cannot be regarded as due to a mixture 

 of families of more than one kind. 



For the solution of the problems presented by the results of these 

 experiments further data are required. The constitution of the F^^ 

 obtained from our other plants heterozygous for short style and for 

 inhibition, throws little light on the case. In these families the 

 distribution of the four kinds of offspring does not depart very greatly 

 from the normal. The numbers obtained are : 



Short-style Long-style 



There are small departures from the 3 : 1 ratio in the cases both of 

 the short- and long-style and of inhibition and colour ; the deficiency of 

 dominants of both kinds has of course a marked effect upon the size 

 of the first category. 



The excess in the two middle classes and the deficiency in the first 

 class appear to be more or less constant throughout the families, which, 

 combined together, furnish the totals given above. 



Short-style and tinge in corolla-tube. In one experiment clear 

 indications were obtained of a coupling between the short-style and 

 a tinge in the corolla-tube just below the level of the anthers. So 

 far as the character of the petals was concerned, the family consisted 

 of tinged- whites and whites ; of the whites, however, some were tinged 

 in the tube, others were colourless. Of the short-styled whites, 20 were 

 tinged in the tube, 1 was colourless ; of the long-styled whites 5 had 

 the tinge and 11 were colourless. The ratio of short- to long-style in 

 this family was very much less than the expected 3 : 1, the numbers 

 being 33 short, 21 long. The asymmetry of the four classes is no doubt 



