47 
Sess. 1907-8.] An Account of a Brachydactylous Family. 
absence of the “ epiphysis ” at the base of the second phalanx. It is possible 
that the epiphysis is also missing, in some instances, from the third 
phalanx, and that the two phalanges (second and third) consist at first of a 
single piece of cartilage. 
There does not appear to be any tendency to revert to the normal type, 
for Nos. 118 (sixth generation) and 163 (seventh generation) will, when 
adult, be quite as abnormal as any member of the fifth generation, and the 
hand (110, fig. 9) is quite as abnormal as that of the father, No. 50. 
The index and fourth fingers seem more aberrant than the second and 
third, as they never show the middle phalanx as a separate bone in the adult. 
Functionally, the fingers are all reduced to the bi-phalangeal condition, 
and thus come to resemble thumbs. One normal member of the family 
greatly offended one of the brachydactylous men by remarking, on one 
occasion, that “ his fingers were all thumbs,” a statement not far from the 
truth. The chief change in the thumb consists in a shortening of the first 
phalanx, which is reduced to a cube. There is no attempt at ankylosis, 
however. An examination of this bone in Nos. 93, 111, 118 (fig. 9), 156, 
and 163 fails to detect any sign of an epiphysis. Does not this support the 
theory that the so-called first phalanx of the thumb is homologous with 
the second phalanx of the fingers ? and, moreover, that the metacarpal bone 
of the thumb is in reality the first phalanx, for here the epiphysis is clearly 
seen at the base, whereas in the other metacarpals the epiphysis is at the 
distal end of the bones. 
The metacarpals vary more or less in different individuals, but, as a rule, 
where ossification is complete, they are abnormal. Where ossification is 
not yet complete, they appear merely somewhat shortened, as is well seen 
in No. 118 (fig. 9). 
The head of each metacarpal is distinctly nodulated in many cases, as in 
Nos. 43, 45, 50 (fifth generation), 88, 95, 96, 99, and 101 (sixth generation). 
The middle one is the shortest of the four in Nos. 45, 99, and 101. The 
fifth shows a distinct tendency to thicken, especially in 45 and 96, as 
well as to become more curved. The abnormal shape of the metacarpals 
is more marked in the man (No. 45) and in his descendants than in his 
sister (No. 43) and her descendants. 
Sesamoid . — Sesamoid bones are well shown in several cases. 
Spaces . — The intermetacarpal spaces are generally increased in width, 
especially between the heads of the bones. This accounts for the com- 
pressibility of the palm laterally. Ossification is further advanced in the 
epiphysis for the head of the metacarpal bones and the bases of the first 
phalanges in No. 163 (child set. 3), than in its cousin’s hands (set. 4). 
