NOVEMBER 13, 1913] 
lambdoid suture (cd and ab) into symmetrical posi- 
tions. In answer to this criticism it may be said 
that the lambdoid suture in this restoration is as 
nearly symmetrical as it is in many ancient and 
modern skulls. Moreover, in the case under con- 
sideration there is the most positive evidence of a lack 
of complete symmetry. Not only is there the most 
striking asymmetry in the whole occipital area 
(compare O and O! and Ce.l. and Ce.r.), but the 
remains of the lambdoid suture itself present a 
marked contrast on the two sides, being quite simple 
on the left (cd), but complex and dentate on the right 
_(b). To base any far-reaching conclusions upon the 
position and direction of an isolated centimetre (b) 
: 
. 
: p. 198) that this will not bring the two halves of the 
: 
of the lambdoid suture (see Nature, October 16, 
p- 198) is simply courting disaster. For every 
_ anatomist knows that the lambdoid is the most vari- 
able and tortuous of all the cranial sutures. 
Another indication of asymmetry of the lambdoid 
suture is the direction of the fragment marked e. 
My critics may say that as it points towards the 
piece cd and not towards b and f, it clearly belongs 
to the left and not to the right half of the suture, and 
that it would fall into its proper position if the left 
parietal were moved wholly to the left side of the 
line mm. But such a deviation as e is quite common. 
A precisely similar thing occurs in the Gibraltar 
skull, and in the La Quina skull there is a Wormian 
bone near the corresponding spot on the right side. 
So far I have said nothing of the right parietal 
fragment (P'). It bears only a very small fragment 
(a) of the lambdoid suture, which, of course, must 
lie somewhere near the line joining e and f. Its 
lower margin does not quite reach the lateral sinus 
at f. With these and other guides (supplied by the 
impressions of the brain and meningeal vessels) this 
fragment may be orientated in a position approxi- 
mately symmetrical to the left side. Incidentally, as 
the point @ must be in the neighbourhood of the 
sutural line on 6, the position of the right parietal 
fragment (P*) so determined checks the accuracy of 
the position of the left parietal (P). 
No exact symmetry between P and P? is attainable 
because the brain itself is not symmetrical. In the 
human brain the type of occipital asymmetry seen in. 
this case (O and O') is usually associated with a 
greater prominence of the right parietal eminence 
(P!). This was the case in the Piltdown brain. In 
further confirmation of the reality of this it is found 
‘that the right parietal bone is very much thinner than 
the left, so that, as in the occipital region, the full 
extent of the cerebral lack of symmetry is not dis- 
played in the outline of the skull. 
_ In making the drawing illustrating this letter I 
have used a cranial cast which Dr. Smith Woodward 
_ kindly sent me a few weeks ago, but have made 
some slight alterations in the positions of the two 
parietal fragments. 
_ In conclusion I should like to say how much I am 
indebted to Prof. Keith for all the help he has given 
me in my investigations, not only by allowing me 
“to make use of all the valuable material in the museum 
of the Royal College of Surgeons, but also by dis- 
cussing with me frankly and openly all the points in 
‘dispute concerning the Piltdown skull itself. In the 
earlier part of July, working with the cranial casts, 
he seemed to me fo have established a good case for 
his mode of reconstruction; but from the moment I 
began to examine the actual fragments (August 13, 
1913, the day after the discussion of the matter at the 
International Medical Congress) I became convinced 
that his solution of the problem was an impossible 
one. It was this personal experience of the import- 
NO. 2298, vor. 92] 
NATURE 
319 
ance of working with the real things that I had in 
mind when I was writing my last letter (NATURE, 
October 30, p. 267). G. Extior Smirn. 
The University of Manchester. 
The Piltdown Mandible. 
In The British Journal of Dental Science of October 
1, there are published some excellent radiograms of 
the Piltdown mandible and of a chimpanzee’s, the 
views having been taken from the side and from 
above. 
In order to compare the outlines of the two 
specimens, I have superimposed tracings taken from 
each (Figs. 1 and 2). 
Fic. 1.—Outline tracing from radiograms of the Piltdown mandible 
(continuous line) and of the mandible of chimpanzee (broken line). 
The similarity of the specimens brought out in this 
way is very striking, for the outlines are practically 
identical. JI have also superimposed tracings of the 
last reconstruction of the Piltdown mandible and of 
the jaw of a young chimpanzee (Fig. 3), and again 
the similarity of the outline is very remarkable. No 
human mandible is known which shows anything 
Fic. 2.—Outline tracing from radiograms of the Piltdown mandible 
(continuous line) and of a chimpanzee (broken line as viewed 
from above. 
like the same resemblance to the chimpanzee jaw in 
outline and in all its details. 
Of the molar teeth, I need only say here that not 
only do they approach the ape form, but in several 
respects are identical with them. 
The cranial fragments of the Piltdown skull, on 
the other hand, are in practically all their details 
Fic. 3.—Outline tracing of the last reconstruc- 
tion of the Piltdown mandible, and of the 
mandible of a young chimpanzee (shaded 
essentially human. If that be so it seems to me to be 
as inconsequent to refer the mandible and the cranium 
to the same individual as it would be to articulate a 
chimpanzee foot with the bones of an essentially 
human thigh and leg. Davip WarTERSTON. 
University of London, King’s College, 
Strand, W.C. 
