A CASE OF HEREDITARY BRACHYPHALANGY 293 

foetal life. The fact that they are here lacking in an eight months 
old child proves conclusively that we are dealing with a malformation. 
Experience from analogous malformations in other material en- 
titles us to expect that later on, also in this individual, some at any 
rate of the finger bones belonging to this second row will appear. But 
since their formation is so markedly delayed they will present a pro- 
nounced shortening. It is in this connection of special interest that 
the ring finger of the right hand on the Rôntgen plate presents a tiny 
ossific centre indicating the first formation of the second phalanx in 
this finger. The fact that this centre of ossification appears first in 
the fourth finger leads to the assumption that the second finger bone 
in this finger will be longer than the corresponding finger bone in 
the other malformed fingers. 
When these facts are taken into consideration it may be said that 
the abnormality found in the hands and feet of the child is the same 
as that with which we are confronted in Hans Olsen’s hands and feet. 
The present difference is due to the fact that the hands and feet of 
the child have not yet completed their development. Striking featu- 
res which prove the correspondence, even in details, between the mal- 
formation of the two individuals are the following: among the mal- 
formed finger bones the second phalanx of the ring finger is in the 
child the one which has first begun to develope. Correspondingly, 
in Hans Olsen’s hands the second bone of the ring finger is the one 
which shows the least pronounced shortening. Moreover, while the 
bones of the thumb are in both individuals normal, the first bone in 
the big toes of the child is still lacking. Similarly the corresponding 
bone in the big toes of Hans Olsen shows a marked shortening. 
The malformation with which we are confronted in Hans Olsen 
and in Karen Hansen’s son Ole Kristian is a hereditary deformity and 
its mode of inheritance is well known. Corresponding malformations 
of hands and feet represent the group of human characters the here- 
ditary relations of which have been most fully worked out. Personally 
I have had the opportunity of investigating such a material, including 
direct inheritance through six generations within a family of 161 in- 
dividuals. 
In the literature I have found thirteen investigations dealing with 
families in which there occurred simultaneous malformations of toe 
and finger bones, related to the one here found. In general it may 
be said that the second row of toe and finger bones is the one which 
is most frequently affected. In all the cases mentioned the deformity 
