PROFESSOR K. PEARSOX AXD OTHERS OX 
322 
While the modal value is conspicuously 8, the mean value is 7‘4639. This is due 
to the second modal value of 5 on the side shoots. The standard deviation is 1'4893, 
and the correlation T899. It will be seen at once how the result fully confiiined my 
expectation, that the degree of resemblance between capsules on the same plant 
would be largely reduced, owiiig to tbe existence of differentiation. Tbe actual 
distribution of capsides in 210 plants was as follows :— 
Number of Seg-ments. 
o 
Frequency. 
•) 
.3. 
1. 
5. 
6. 
7. 
8. 9. 
10. 
11. 
12. 
13. U. 
15. 16. 
17. 
18. 
19. 20. 
Total. 
1 
1 
5 
75 
108 
133 
420 
61 
19 
10 
8 
2 0 
■ 
0 1 
1 
0 
0 
0 1 
845 
Thus on an average there were four seed vessels to a plant. The mean and standard 
deviation found directly from the capsules are 7’5101 and 1'4559 respectively. 
These are in substantial agreement with the above results found for pairs. They do 
not confirm the conclusion based upon the data for poppies, namely that if we work 
with pairs we shall raise the mean and lower the variability. The fact is that vigour 
seems to work in opposite directions with this plant and the poppy ; with the latter 
it means many capsules rvith a high number of stigmatic l^ands, but with the former 
it means many side shoots with the difterentiated capsules with few segmentations. 
Such capsules of course decrease the mean and raise the variability. 
The coefficient of variation is 19■38.5, sensibly greater than that of the wild pop])y, 
but below that of the holly leaf. The standard deviation of an array is 1'4622, or 
the variability of the individnal 98'18 per cent, of that of the race. The plant with 
the greatest number of seed vessels on had only 11, and these gave a standard 
deviation of 1’6188, greater than that of the whole race ! But of course this is subject 
to a very large probable error ; it suffices to emphasise, however, how the soui'ce of 
variation is to be sought within the individual, and is not a mere result of sexual 
reproductit)n. 
The following table sums up the results obtained for Nigella Hispanica :— 
Xumber of 
Mean. 
8. 1). 
Coefficient 
of 
variation. 
S. D. of 
array. 
Per¬ 
centage 
variation. 
Plants. 
Capsules. 
Pairs. 
Pairs. 
Capsules 
1—i 
o 
845 
3212 1 
7-4639 
7-5101 
1-4893 
1 - 4559 
19-385 
1-4622 
98-18 
(14.) D. Mallow (Malva Botundifolia).—I had given up the idea of the ordinary 
wild mallow [Malva sylvestris) owing to the few plants to be found in the neighbour¬ 
hood of Hampden, as Avell as on account of the immense number of seed vessels on 
the plants to be counted. But one day an Inspection of my potato-patch revealed 
