Karl Pearson and David Heron 
the tails. If there i.s a gap between the defective and the normal members of the 
same sibship, intermediates in plenty will be found elsewhere. The whole difficulty 
associated with the Government Bill for the care of the feeble-minded turns on 
the questions how and where to draw the line between the " normal " and " feeble- 
minded." Whatever may be finally done, it is quite certain that there will be 
no real distinction between two individuals who fall just one side and just the 
other of the dividing line. Even the personal equation of trained observers will vary 
in classification, and Mr Yule takes the untrained record of thousands of the laymen 
who make census returns as marking off in some manner a " discrete" character of 
"mental defect." Absolutely the same remark applies to nutrition. The boundary 
of "low nutrition" is also an arbitrary dichotomy in a continuous variate fixed 
by the personal equation of the observer. (7) tells its own tale, for it is based on 
continuously changing and measurable characters. (8) is less obvious, but not 
only in number, but in quantitative intensity " nerve signs " are really continuous. 
To these also we may add mental derangement (9) ; there is a very great range 
of variation in imbecility and idiocy as we have already indicated under mental 
dulness. If we turn to " blindness" (10) the source of it may be most varied, but 
if we define it merely as the loss of the faculty of sight, there is, as the simple cases 
of either congenital or senile cataract might have shown Mr Yule, almost every 
iutensity of the failure of sight. Even certain cases of albinism are to be found 
in the Blind Asylums and are educated as semi-blind. Semi-blindness is so well 
recognised that special schools have been started for the semi-blind by certain 
educational authorities. In Bristol out of 22 children sent to the Blind Asylum 
at the expense of the Education Committee 13 had some degree of vision, and 
7 could read large print with varying degrees of difficulty, and were able to do 
some form of handwork by sight. Out of 75 children specially examined for eye 
defects at Bristol in 1911, beyond those requiring glasses were 9 suitable for the 
partially blind class*. Of (11) deaf-mutism, we are less competent to speak, but 
we have been informed by the very best authorities it is far from an absolutely 
fixed condition and that it has a great variety of grades. The grades are more 
marked in the acquired than the congenital cases, but in the latter cases they 
vary with the cause of the congenital deafness. Cases even exist with slight 
degrees of deafness which would probably have been associated with mutism had 
the deafness been more considerable. Different degrees of hearing are found among 
deaf-mutes. There are scores among them who undoubtedly possess an amount of 
vowel hearing, and it helps the tone of their voices when they are being taught 
articulation; this is true, although they canuot distinguish speech without watching 
the lips and without their ears being within two or three feet of their interlocutor. 
* We have had before us the diary of a man who "went blind" in old age. At 70 the writing 
is perfectly clear and legible. It closes at 80 with the words scrawled in an almost unreadable 
trembling hand across the page. " I am now almost blind and with great difficulty I write this. 
Oh! the misery I feel, no one comprehends it. — " When was this man "blind" for a census return? 
Tbe category " blind " covers a vast range of cases of partial sight, and it would be hard to draw a 
dividing line between "blind" and "normal" in such cases. 
