122 
Inheritance in the Foxglove 
the small variations would be fluctuating, non-inheritable variations ; but the 
results in the present case are definitely against a supposition of this kind. 
It might be urged by some that the result is really due to the existence of 
genotypes, and that variations within the limits of each genotype are not inherit- 
able. The distributions of the families in the table do not indicate the occurrence 
of genotypes of any considerable magnitude. If the genotypes are supposed to be 
very small the practical result would become indistinguishable from the inherit- 
ance of continuous variations. 
7. Ratio of Breadth to Length of Corolla. 
The breadth was measured as the maximum horizontal width across the 
mouth of the corolla of a fully expanded flower in which the anthers had opened ; 
the length was the maximum distance measured along the mid-adcauline surface 
with the lower lip stretched out straight in the long axis of the flower. It is 
convenient to express the ratio in the form, 1000. The mean of the 
Length 
ratios of the four lowest flowers of an axis was taken as the mean of the plant. 
The original parent plants varied widely in this ratio, and the families raised 
by selfing tended to have the same ratio as their parents. 
A plant bearing wide flowers was crossed with one having narrow flowers, and 
the offspring tended to be intermediate. On selfing these offspring the new 
generation exhibited, of course, considerable variation, but taken as a whole the 
intermediate condition was retained, and there was clearly no segregation into 
wide flowers and narrow flowers. Thus, the different degrees of this character 
blend readily on crossing, and the mode of inheritance is very similar to that of 
the spotted condition. 
The results of a multitude of crossings of plants bearing variously shaped flowers 
have been carefully determined and tabulated, and there is no question about the 
general accuracy of the statement made above. In the present place we may 
confine our attention to the self-fertilised generations of Series II and III (p. 123). 
A plant { % Ci) with relatively wide flowers (ratio 608) was crossed with a 
plant ((/ jBj) having relatively narrow flowers (ratio 487). The family (= II) had 
flowers approximately intermediate. The reciprocal cross = III. The distributions 
of the families of the various generations raised by selfing are shown in the 
accompanying table. The families of- each generation are given in an ascending 
order of the ratios of the parents. As in the case of the character of spotting it 
will be seen that there is a clearly marked tendency for the mean ratios of the 
families to approximate to the ratios of the respective parents. In none of the 
families do we find any definite segregation into plants with wide flowers and 
plants with narrow flowers resembling those of the two progenitors of the series. 
Wide and narrow races could be raised by selection using only self-fertilisation. 
Thus in family III with a mean ratio of 531 there was a single plant (III 2) 
with as high a ratio as 575. This was selfed and the mean ratio of the offspring 
