114 
Inheritance in the Foxglove 
In the last table, p. 113, a correlation surface is shown between parents and 
offspring. It is formed from the series of families given in the table preceding the 
last, and arising by self-fertilisation. 
The constants calculated from the table are : standard deviation of weighted 
parents 1'7805 units, and of offspring 1'8962 units, coefficient of correlation "707. 
In this table 39 families were involved, as detailed in the previous table. 
The starting points were four homozygous dominant plants occurring in the two 
families raised from the reciprocal crosses {G^ x B^) and (i^j x C,). 
3. Brown Spots. 
The amount of spotting on the inside of the corolla is not closely correlated to 
the intensity of the general purple coloration of the flower, for even in white 
plants the spots may be numerous and of a deep purple colour. In coloured 
plants the spots were almost always dark purple. As a very rare exception in the 
coloured plants (4 plants in about 2500) some of the spots were russet brown, and 
in the case of the larger spots there was a iniddle area of brown bordered by a 
margin of purple. In white flowers the spots were fairly frequently brownish- 
green or brown. In such brown spotted white flowers I could never detect the 
slightest tinge of purple on the general surface of the corolla, while in purple- 
spotted white flowers a faint tinge of purple could often be seen. The brown 
spots of white flowers might not become visible until the flowers were on the 
point of fading, and in the case of any given white plant it was wholly impossible 
to affirm that brown spots were, or would be, entirely absent from all of the 
flowers. 
With the exception of the four plants mentioned above there was a sharp dis- 
continuity to the naked eye between purple spots and brown spots, intermediate 
conditions being absent. The brown colouring matter may be regarded as altered 
or decomposed anthocyanin. In purple spots a microscopic examination often 
showed a certain amount of decomposition ; but, with the exception of the four 
plants, the amount was not enough to alter the colour of the spots sufficiently for 
detection by the naked eye. Thus, the discontinuity lies between a normal small 
amount of decomposition, and an abnormal entire decomposition. It may be 
stated that under ordinary circumstances brown or greenish spots (as seen by the 
naked eye) are linked to a perfectly white corolla, but purple spots occur in both 
purple and " white " flowers, and an apparently perfectly white corolla may also 
bear purple spots. 
If a brown spotted plant is crossed with a purple spotted one the offspring are 
all purple spotted and heterozygous. The brown spotted condition is inherited in 
Mendelian fashion, and is recessive to purple spots. 
No special crossings have been made to investigate the matter, and the results 
which ai'e given below are merely picked out from the records of the numerous 
families which have been raised for other purposes. 
