545 
whole of the next night, always having a picture of the forceps in 
her mind’s eye. This incident she declared had been the cause of 
the abnormality, and the two thumbs had certainly a superficial re- 
semblance to the beak of a dental forceps. This explanation of course 
cannot get any credence scientifically, although many authors give 
“maternal impressions” a position of prominence. The fact that the “im- 
pression” in this case occurred between the third and fourth month, 
does not align itself with embryological facts, namely, that the digits 
are formed and completely separate at the ninth week, therefore this 
condition of fission must have been present at least one month before 
the impression. 
In this case there seemed to be slight movement of the accessory 
thumb, but on removal there appeared to be no distinct synovial mem- 
brane between it and the tumb 
metacarpal proper but only fibrous 
union. 
The supernumerary digit came 
off slightly more than half way 
down the metacarpal, which is 
manifestly deformed and showing 
a tendency to assume a Y-shape, 
which is completed by the lowest 
segment of the extra-digit. 
Both the normal and the 
supernumerary thumb were per- 
fectly normal in appearance and 
both had well developed nails. 
The left hand was the only ex- 
tremity affected, all the others 
being absolutely normal. No other 
physical defect was found in the 
child. (Fig. 1.) 
Case 2. That of EM. a Fig. 1. 
boy of 5 years, differs from the 
previous in not being such a deep fission and in only having two pha- 
langes in the extra digit instead of three as in the previous case. It 
is noteworthy that the skiagram of this case shows no epiphysis for 
the proximal phalanx of the supernumerary digit. 
The family history in this case was also negative and there was 
no polydactyly nor syndactyly in any of the near relations. The left 
hand in this case as in the last was the only one affected. Here there 
Anat, Anz, Bd. 40. Aufsätze. 35 
