69 
supination give strong confirmation of the similarity of the joints. 
The photograph shows something of a tendency to flexion and pro- 
nation of the hand at the wrist, which Dr. JoLLY does not allude to, 
but it certainly is far less marked than in this case. It is hardly 
possible to doubt that, except in the condition of the wrist, the cases 
were similar in all important respects. It is not easy to guess what 
relation there can be between want of development of the shoulder 
muscles and this malformation of the hand and arm; but the simul- 
taneous occurrence of these conditions in two cases cannot be regarded 
as accidental. 
Mr. Murray’s case is less fully reported and the resemblance is 
less striking, but they probably are of the same nature. 
The question as to the cause and the process of production of 
this deformity is very interesting but very obscure. The theory that 
amniotic folds may have caused a mutilation, probably a splitting, 
which is followed by an attempt at duplication is at first sight a very 
attractive one. Certain experiments on lizards’ tails give it support 
from analogy. It accounts for cases in which the lesion was so slight 
that but a part of one finger is involved, or so deep as to affect 
a whole extremity. There are, however, certain very serious difficulties. 
What, it may be asked, becomes of the parts that should form the 
radial side of the hand in a case like the present one? Another 
difficulty is that in a large proportion of the cases both hands and 
both feet are affected. ZANDER !) argues that there is no impossibility 
in the occurrence of symmetrical lesions by the amnion. In support 
of his views it may be stated that very often, perhaps usually, these 
malformations of both sides are not absolutely symmetrical, and there- 
fore the more likely to have such an injury for their proximate cause. 
If these objections can be met this seems the most promising theory. 
TARUFFI, while admitting our ignorance, speaks of ,,exaggerated gem- 
mation“, which conveys no explanation. All are agreed that there is 
nothing to be said in favor of a double germ. It is remarkable that 
this view should have survived so long. A century and a half ago 
M. de Marran?) wrote on this subject: „Il faut dévorer bien des 
prodiges, lorsque on dit du bout des lévres que la formation des 
monstres peut étre expliquée par la confusion des germes.“ 
Harvard Medical School, Boston, 
August 4, 1892. 
1) Virchow’s Archiv, Bd. 125, S. 479 and 480, 1891. 
2) Hist. Acad., 1742. 
