348 
PROFESSOR K. PEARSON AND OTHERS ON 
and 25 leaves from each of 58 plants by me, in the neighbourhood of Great Hampden 
in Buckinghamshire. Care was taken to avoid the reproductive shoots with their 
larger uncut leaves. The Hampden plants were, I feel certain, a fairly homogeneous 
group, the plants were young runners up the trees, only a few feet in length. The 
Canterbury 2 )lants appear to have had a somewhat larger leaf, although in themselves 
an apparently homogeneous group. 
It would undoulhedly have been better to liave had the leaves collected by one 
person from one district; but until the leaves had all been measured and their 
indices found, I did not know of this difterence between the two groups. It was very 
little noticeable in the table of index distriljution, but became manifest to me when 
finding the homotypic correlation table of the absolute lengths, v.diich I did in two 
sections, one for either group. The very considerable labour involved in measuring 
and determining the indices of 250U leaves precluded a repetition of the work on 
more homogeneous material. The whole of this labour was undertaken b}' Dr. 
Warrex, who further formed the table and determined the correlation coefficient.* 
I give in the following scheme the frequency distribution of the indices to show 
its, uniformity. 
Index. 
•295- 
■305. 
•395- 
■495. 
1 . 
lO 
Ci o 
i-O 
1 . 
»-o 
1 . 
o o 
CC 
•795- 
•895. 
1 . 
uf to 
ct o 
X o 
1 
to to 
c; CO 
a O 
1 . 
to o 
CO CO 
o 
1 . 
to to 
CO CO 
I— 01 
1 
to >o 
n o 
01 CO 
I . 
to to 
Ci ct 
CO -t 
to to 
-r lO 
! . 
to to 
c: 
lO to 
Total. 
^ i-H 
I—' 
'— 
Frequency 
2 
10 
38 
219 
674 
738 
136 
207 
86 
32 
16 
_ 
8 
3 
1 
2500 
* After measuring the gills of only 1070 mushrooms, I very fully appreciate Dr. 'Warrf.n's task on 
the 2.500 ivy leaves ! 
