THK JTRADSHAW LECTURE 25 



as among a large number of candidates this is sure 

 to happen occasionally. But the table on p. 24 

 signed by seventeen different teachers, signing 

 altogether thirty-three times for each student, 

 shows a uniformity which could not be the result 

 of accident. Out of all these sixty-six signatures, 

 there is but one variation. One teacher put 

 " excellent " instead of " very good indeed," terms 

 regarded at the hospital as equivalent. In the 

 opinion, therefore, of seventeen teachers, the 

 abilities of these twins were indistinguishable or 

 identical.* 



Dissimilar Twins. 



The difference between twins developed from 

 fertilisation of separate ova may be emphasised 

 by disease occurring in one whilst the other 

 escapes. Dr. R. Hutchison exhibited at the 

 Children's Section of the Royal Society of Medicine 

 twin brother and sister, aged a year and a half, the 

 girl being the subject of well-marked achondro- 

 plasia whilst the boy was healthy. 



A photograph of these he has kindly allowed 

 me to reproduce (see Fig. 1, p. 26). 



By the kindness of Dr. Shuttleworth I am also 

 able to show a photograph of twin patients of Dr. 



* For another case of identical twins see Appendix. 



