36 Proceedings of the Royal Society of Edinburgh. [Sess. 1907-8. 
some apparently identical cases seem to have been observed by him in 
America. His cases, in fact, are so similar to mine that I am inclined 
to think they must be descended from an abnormal member of the 
English family, four generations back, who migrated to America, but 
of whom no tidings have since been received by his relations in this 
country. 
My conclusions as to the precise nature of the abnormality differ 
from those of Farabee, who thought the essential feature was the 
absence of the middle phalanx. I have seen every surviving abnormal 
individual in this country, twenty-five in number, as well as most of 
the normal ones, and as a result of my investigations I am able to 
confirm my patient’s statement with regard to the extent of the peculiarity, 
namely, that whenever it occurs, all the digits of both hands . and both 
feet are abnormal, and the abnormality is, in all cases, practically 
identical with that exhibited by my patient, though varying somewhat 
in degree in some of her relatives. As the result of a great deal of 
correspondence, and inquiries made locally, it has been possible to 
construct a genealogical chart showing seven generations through which 
the abnormality has occurred, and to make this chart complete as to 
the number of individuals in all the last five generations (fig. 1). The 
third generation is also complete as to numbers, but incomplete as to 
the sex and exact proportion of abnormals and normals, but only one 
individual can now be traced in the first, and one in the second, genera- 
tion. The chart includes 174 individuals, of whom 107 are living. I 
have also taken a good number of measurements of 86 of these individuals. 
They are given in an appendix to this paper. 
Views of heredity held by many students of biological science at the 
present day differ very considerably from those held up to the close of 
the last century, owing to the belated discovery in 1900 of the work 
of Gregor Mendel, in which he gave an account of some extremely 
interesting and important experiments carried on by him in the sixties. 
Mendel propounds new theories based on his observed facts, and these 
theories, whether true or false, will serve as good working hypotheses 
for some time to come. My own observations were undertaken primarily 
with the object of recording facts, and without any bias resulting from 
the study of Mendel’s published work. However, one can hardly fail 
to recognise the support that these facts give to Mendel’s laws of 
inheritance. 
One of Mendel’s laws is as follows : — Among the descendants of two 
parents, one of whom is normal and the other is in possession of a 
