MR. G. UDNY YULE ON THE ASSOCIATION 



at least, however, if not in four, the negative sign appears to be certainly significant ; 

 I refer to the partial associations of A and B | AB | yD , | AB | OS | , and | AB | CD | , in 

 which cases all the twenty-four coefficients for both sexes are negative : and the one 

 partial coefficient | BC | aD | , seven out of the eight examples of which are negative, 

 the one positive value (Girls, Standards I. -III.) being only 1/1 5th of its probable error. 

 The first case is the most general and remarkable, but in both it will be noted we 

 are dealing with an association of nerve signs. As might be conjectured from the 

 generality of the sign, | AB|C| and | AB|D| are also negative, i.e., when individuals 

 exhibit either low nutrition or mental dulness, or both, the presence of nerve signs 

 lessens the probability of development defects being present and vice, versd. 



This case is most remarkable, and the following figures, showing the chance of an 

 individual exhibiting development defects (or nerve signs) when he exhibits nerve 

 signs (or development defects), and so on, illustrate it further. Multiplied by 100 

 the chances can, of course, be read as percentages, i.e., 50 per cent, of C's are A, but 

 only 42 per cent, of EC's are A (for the boys), and so on. 



A. Development Defects. B. Nerve Signs. C. Low Nutrition. D. Dulness. 



In every case the presence of B is antagonistic to that of A when either C or D 

 is present ; and A is similarly antagonistic to B. I am quite unable to suggest any 

 possible explanation of this, but so unexpected a result ought to throw some light on 

 the physiological relations between the signs observed. It is particularly curious to 

 note that A and B are negatively associated in the presence of either of two defects 

 so apparently different as mental dulness and low nutrition. The point seems to be 

 worth further investigation by the committee.* 



* Note 4/4/00. Dr. E. B. SHULDHAM writes to me as follows : " My experience with boys at the Bisley 

 farm schools was that many of the boys who had left poor homes in London with insufficient feeding suffered 

 from suppuration of the cervical glands a few weeks after their removal to Bisley, also to a great change for 

 the better in food, clothing, and shelter. After a prolonged residence at Bisley the glandular enlargements 

 lessened, and the suppuration ceased." This is interesting for comparison with the above, as we have here 



