of Fingers and Toes, and of the Phalanges, in Man. 103 
side 4 inch, and 4 an inch along the middle. The position of the 
base of this wedge-shaped additional bone is shown in the sketch 
by the double protuberance on the radial side. Between these a 
depression may be felt corresponding to the short shaft between the 
two articular ends. The distal phalanx is an inch in length. The 
measurements were made exactly from the joints, avoiding the 
error of including the knuckle twice. 
When the thumb is straightened, its point passes a sixth of an 
inch beyond the joint between the proximal and middle phalanges 
of the index finger. The thumb of the right hand scarcely ad- 
vances so far as that joint. The unusual length of the thumbs in 
this case is gained by the proportionately greater length of the 
proximal phalanx and by the presence of the additional bone, while 
the distal phalanx is a little shorter than usual. At the joint on 
the proximal side of the additional phalanx there is the usual 
extent of flexion and extension. Between it and the distal phalanx 
passive motion is free and readily felt in both thumbs, although it 
cannot be carried so far as to cause an angle or additional knuckle. 
Some motion in the lateral direction also can be made at this joint. 
The utility of the thumb is not impaired. The fingers are longer 
than usual (their lengths, from the metacarpo-phalangeal articula- 
tion, are, fore-finger 3%, middle 48, ring 42, little 33, inches. 
The whole hand is 8 inches in length), present the usual propor- 
tionate length, and have three phalanges each. The great toes 
present the usual length, size, and number of phalanges. He is of 
full average stature, his height being 5 feet 94 inches. 
A maternal aunt had the same kind of thumb on the right hand, 
being the only instance of the occurrence of the peculiarity in any 
relative of the family. This aunt has a son and three daughters. 
The mother had other three sisters and two brothers, all of whom, 
except one of the sons, have families of sons and daughters, The 
mother never heard that any of her ancestors had it. 
REMARKS. 
As some of the cases in the hereditary group show the 
tendency to have passed over at least two generations and 
then to have reappeared, it is possible that some of the cases 
recorded as original, may be cases of distant inheritance. 
But it must have had a beginning in these too. Careful 
inquiry was made in all the cases, and the previous occur- 
rence of such a thing in the family is pretty sure to be 
brought up when a child is born with it. The cases one 
would feel most inclined to doubt on this score, are those in 
which it appeared in more than one child of the family, 
as in cases 1,8, and 9.* In such cases we may suppose the 
* Tam indebted to Dr Strachan, of Dollar, for a case (which has arrived 
too late for detailed insertion at present) closely resembling Case 1. In a 
