198 
brain cast obtained in Dr. Smith Woodward’s recon- 
struction; Fig. 2, the same view in a reconstruction 
of the skull made by the writer: Fig. 3, the same 
view of a brain cast from the skull of an Australian | 
native, with a cubic capacity of 1460 cubic centi- 
. 
eee —— 
Sa—- n= 
LA (| 
vr iy 
Fic. 2.—The same aspect from the reconstruction of the skull by the writer. 
ved 
50 
metres—rather a large skull for an Australian native. 
All three brain casts have been arranged on the same 
horizontal plane and drawn to the same scale. To 
facilitate comparison, they have been placed within 
squares of the same size. Three vertical lines are 
1s 50 50 aw 
Fic. 3.—The same aspect of the brain cast from the skull of an Australian 
native—for comparison with figs. r and 2. 
represented—the middle and two lateral lines. 
lateral lines are 50 mm. apart from the middle line. 
The leading principle which guides the task of 
reconstruction is symmetry—the right and left halves 
of the mammalian head and skull are approximately 
NO. 2294, VOL. 92] 
NATURE 
30 
The | 
[OcroseR 16, 1913 
| alike. When the test of symmetry is applied to the 
| occipital region of the brain cast from Dr. Smith — 
| Woodward’s reconstruction of the skull, it is at once 
seen that there is a great degree of discrepancy — 
| between the right and left halves; the amount which 
' has to be added to the right halt to make it ap-— 
proximately equal to the left is shown by the stippled 
line in Fig. 1. The discrepancy between the two 
halves is even more marked when the right and left 
halves of the lambdoid suture—the joint between 
the posterior margin of the two parietal bones and 
the occipital—are investigated. 
The situation of corresponding parts of this suture 
are represented on the right and left halves of the 
* recovered parts of the Piltdown skull; Dr. Smith 
n Woodward has already recognised the presence 
sy of thoce two parts of the lambdoid suture. 
fs They are indicated on the three accompanying 
figures as A, B. Now on the left side of the 
skull the lambdoid suture cuts the lateral line 
50 mm. from the mid-line; on the right side it falls 
20 mm. short of the lateral line; to make the two 
© sides approximately symmetrical, the right lambdoid 
suture has to be moved outwards until it occupies 
the position A’ B/, shown in Fig. 1. That degree 
of error exceeds even the amount found in human 
skulls deformed artificially or deformed by disease, 
and points to an error in reconstruction. It will be 
also seen that the right and left halves of the suture, 
as indicated on the brain cast—the discrepancy is 
even more marked on the reconstruction of the skull 
—have a different inclination to the mid-line of the 
reconstruction. It may be thought that all that is 
necessary to obtain symmetry is to move the parts of 
the right half outwards until the right and left halves 
of the brain cast are approximately equal in size; 
when this is done, it will be found that marked 
asymmetry of another kind is introduced. In 
moving one part, all the other parts of the skull are 
thrown out of place; the task has to be recom- 
menced from the first initial step. 
In Fig. 2 I give a drawing of the brain cast ob- 
tained when the parts of the skull are placed 
together according to their structural markings. 
There can be no doubt as to the middle line of the 
occipital bone; on its outer surface is clearly seen 
the ridge which indicates the division between the 
right and left halves of the neck. We may presume 
so in this primitive man that the neck was symmetrical. 
The next point which has to be fixed definitely is the — 
,, middle line on the roof of the skull. At first I accepted 
the middle line as fixed by Dr. Smith Woodward— 
an elevation on the outer aspect of the left parietal 
bone—near its hinder upper angle—corresponding to a 
wide depression which is to be seen on the inner aspect 
of that part of the bone. I found it impossible to 
obtain even an approximate symmetry of the right and 
© left halves of the skull in all my attempts at recon- 
struction when I proceeded on _this basis. 
On comparing the corresponding regions of the 
Piltdown and Neanderthal brain casts, it became quite 
apparent that the markings of the middle line— 
which I had accepted from Dr. Smith Woodward— 
did not represent the middle line, but a region well to 
the left of that line. The excavation or groove which 
we had regarded as caused by the longitudinal blood 
sinus—a channel passing along the roof of the skull 
under the middle line—was not due to that struc- 
ture, but to the well-marked elevations of the brain 
on each side of the longitudinal sinus. These cerebral 
elevations are clearly marked in the brain casts of 
| Neanderthal man. In the skulls of all the higher 
| primates, the longitudinal sinus, near the hinder end 
of the adjacent margins of the right and left parietal 
bones, is marked by a narrow deep groove with dis- 
