K. Pearson 
135 
and mistresses of nearly 200 schools in wliich observations have been made for me. 
In the midst of arduous professional claims on their time and energy, they have, 
in many cases at considerable personal inconvenience, recorded and measured the 
children in their charge, for a purpose only dimly foreshadowed to them. In no 
case could they realise on the basis of their own 10 or 20 schedules the value of 
the scientific inquiry to which they were contributing, for its success depended 
entirely on the combination of tens and twenties into hundreds and thousands, 
a possibility which even some of my keenest assistants despaired of during the 
years in which the investigation was in progress. We were, indeed, more than once 
confronted by an apparent drying up of all conceivable sources of new material. 
The number of schools is of course immense, but the means of reaching and 
interesting their masters and mistresses extremely limited*. It is only right and 
proper to place on record the names of my chief co-operators in this investigation. 
See Appendix II. 
The list in Appendix II. will not only show the class and range of the schools 
dealt with, but also the great variety of localities which contributed. As far 
as the United Kingdom contains local races, we have fairly sampled them. Of 
course one would much prefer to have dealt entirely with a single district with 
little immigration, and thus have worked wholly within one local race, but a little 
consideration showed how impossible it was to get material enough for any safe 
conclusions from such a limited area. It is not one per cent, of teachers who 
can spare the time, or, being able to spare the time, have the imagination 
which will induce them to aid in co-operative inquiry of this kind. With the 
assistance of Mr E. W. Adair an attempt at a limited area was made in the 
case of Guernsey. But we only succeeded in getting 150 to 200 schedules filled 
in. These were sufficient to show that a perceptible differentiation in the physical 
characters existed between Channel Island and English children. No differentia- 
tion in the psychical characters could be observed. Accordingly the Guernsey 
children were not pooled with the others for physical characters, but the material 
was far too insignificant in amount to justify a separate investigation of the statis- 
tical constantsf. The influence of local race would undoubtedly make itself felt 
on our statistics, but taken broadly our constants represent the condition of things 
in the nation at large, and if any portion of the relationship between brothers 
and sisters is really due to local race, then we must inquire whether local race 
is or is not equally influential on the moral and mental characters. My belief 
* I must not omit to acknowledge the courtesy of the editors of the Journal of Education, The 
Scliool World, The Schoolw.aster and other educational journals in publishing my appeals. 
t While showing a certain differentiation, the general accord between the Guernsey correlations and 
those of the United Kingdom was remarkable, and extremely satisfactory when we want confirmation of 
the fact that, within broad lines, we are dealing with general " human " characters and relations, and not 
with something peculiar to "local race." As an instance I cite the "correlation ratio," t], a constant 
determining association, — for the case of head growth with age in girls. Guernsey Girls: ri = -i4; 
English Girls : Ti — -i6. Considering that this Guernsey result is based on 110 cases only, the agreement 
is remarkable. We are clearly dealing with a constant of human growth in general. 
