368 



can make a projection from the navicular pointing backward, he goes 

 on to say that the development of the tuberosity of the navicular by 

 no means depends upon this, which is of course in contradiction with 

 his previous view. Pfitzner himself has shown that a large tuberosity 

 may coexist with a well-developed free tibiale externum. Therefore the 

 first statement must be withdrawn. In fact Pfitzner withdrew it 

 himself, though without modifying his theory. Yet there are cases in 

 which what seems to be a tibiale externum is found fused with the 

 navicular and pointing backward with a distinct line of demarcation 

 and clearly in the place of the tuberosity. Which is it? 



If one wishes to demonstrate Pfitzner's views to a person ig- 

 norant of them, the most striking example is the styloid element of 

 the carpus. One mentions that the embryonic carpus shows the group 

 of cells representing this element in nearly 70°/o, that as a rule it 

 fuses with the third metacarpal, projecting into what might be called 

 the territory of the magnum, but that it may instead fuse with the 

 latter, making the line between these bones a transverse one, or it 

 may fuse with the ulnar border of the trapezoid, or finally it may 

 persist as a separate bone. The demonstration is absolutely dia- 

 grammatic and convincing till one finds that not very rarely the 

 styloid is distinctly in two places at once. Though apparently fused 

 with the magnum it may be manifested by a little knob on the meta- 

 carpal, and the more carefully one looks for such cases the more 

 frequently they are found. Now what are we to say when we find a 

 swelling both on the base of the metacarpal and in the distal radial 

 dorsal angle of the magnum? Is the styloid element in two places? 

 Or is it in one of these places, and has the other element attempted 

 to reproduce the ordinary state of aöairs by developing out of itself 

 a styloid process? If one has done it, which one? Or if one can 

 do it, why not both? If both do it, what has become of the styloid 

 element? And be it noted that this element is a real thing, for as a 

 rule it is found in embryonic wrists. 



The secondary cuboid is often very puzzling. Pfitzner described 

 it as a process of the cuboid articulating with the head of the astra- 

 galus. It is of course on the plantar and inner side of the cuboid, 

 and when well-marked is a very prominent projection. It has never 

 been seen free^). Very frequently it appears on the lateral plantar 



1) Pfitzner says somewhere that Schwalbe has such a specimen, 

 and I have described one — now in the Warren Museum — in which 

 it probably was free earlier in life. 



