III. Inheritance in Shirley Poppy 413 
TABLE IV. 
Fraternal Correlation, Record of Apical Flowers. 
Character 
Crop 
Mean 
Oxford, 
Kidderminster 
Arneliffe, 
Parkstone, 
Streatham, 
1900 
11, 1903 
1903 
1903 
1903 
Stigmata 
•26 
•33 
•38 
•14 
•16 
•25 
Colour of Middle Third... 
•34 
•43 
•38 
•41 
•31 
•38 
Breadth of Margin 
•19 
•29 
•21 
■15 
■14 
•19 
Number of Petals 
•23 
•25 
•16 
■28 
■17 
■22 
Extent of Basal Patch . . . 
•22 
•24 
•16 
■18 
■06 
•17 
Colour at Margin 
■28 
•28 
Wrinkling 
•21 
•16 
•12 
■11 
■06 
•13 
Petal Length 
•28 
•28 
Mean 
•24 
..8 
•23 
■22 
•15 
•24 
Accordingly, applying this to the case of two brothers, -with a standard devia- 
tion in their generation of s, and an unselected standard deviation a, we conclude 
that if a generation of any population be subjected to a selection of stringency 
s/a = yu,, the correlation of brothers r will be reduced to a correlation p where 
Now if ?' = ^ be the true correlation of half siblings, what must be the intensity 
of selection /x required to reduce this to p = •l.o ? 
Substituting, we at once find yu, = "TG^S. 
Now can we suppose that a selection of this stringency has been at work at 
Streatham ? It would involve a reduction of about 25 per cent, in the variability 
below the normal variability of the Shirley Poppy. Now the only data we can 
judge from are the first three crops which give a mean fraternal correlation 
of •25 ; and the only character for which we know their absolute variability is 
their number of stigmatic bands. These give a mean variability of 2'055, which 
is practically equal to that in the general Shirley population. Accordingly the 
selected variability of the Streatham poppies ought to be 2-055 x •7645 = 1^57l. 
The actually observed value is 1'507. In like manner the Parkstone crop which 
shows the next greatest reduction in the fraternal correlation has for its reduced 
stigmatic band correlation '14, which should mark a reduction in stigmatic band 
variability from about 2 to 1^57, the actual value observed being 1^56. Without 
laying too much stress on isolated accordance in a very irregular table of this 
kind we may reasonably conclude that the great apparent reduction in the 
Streatham correlations, and to a less extent the reduction in the Parkstone, can 
