570 REPORT—1883. 
-equalising the process of filling the skull and ascertaining its cubage, is open to the 
serious objection that the quantity of seed which can be introduced into the skull, 
and likewise the space it will occupy in the measure, depends upon the amount of 
tapping practised. There being no means of regulating this, the result obtained 
depends upon the observer. Variations to the amount of 25 to 40 c.c. are not un- 
frequent in different measurements of the capacity of one and the same skull by 
the same observer. Broca, some years ago, introduced a system of measuring the 
-eapacity with shot, according to a method whereby the measurer is made to play a 
secondary part, the accuracy being dependent upon the system which has been 
minutely described in his work on craniology. By this system the skull is filled as 
full as possible with shot of a given size, according to certain directions which he 
gives. The quantity which has been introduced into the skull is then measured in 
glass vessels according to a fixed plan. The results of this method show that the 
variations between different manipulations on the same skull do not vary more than 
from 5 to 10 c.c., any greater variation than this occurring indicates that some error 
has been made in the process. The advantages of this method at first sight appear 
to be very great, but unfortunately the results obtained from it are somewhat greater 
than the actual capacity such as would be obtained by filling the cranial cavity with 
fluid. This error is, however, a relative one, and can be corrected by ascertaining 
how much the capacity measured with shot is greater than the actual capacity. 
This can be done by careful measurement of some test skulls rendered impervious 
to fluids, with shot, and water or mercury. Notwithstanding its disadvantage in 
this respect, the author thinks Broca’s method is the most trustworthy and the best 
-one for estimating the capacity, and would therefore recommend its adoption. 
3. A new Method of comparing the Forms of Skulls. By W. 8S. Duncan. 
The author brought forward a new method of comparing the forms of skulls so 
as to bring out their relative characters by the superposition of their outlines. 
Outlines in profile had first to be made full-size from the actual skulls ; marking 
the basion, the alveolar point, and the glabella or the nasion very carefully, then 
drawing the basi-alveolar line and dropping a perpendicular to the latter from the 
glabella or the nasion. All the skull outlines must then be re-drawn to suit a 
common standard height of the glabella, or of the nasion, above the basi-alveolar 
line ; that is, the perpendicular from the glabella (if that point be used) must be 
the same in all the outlines to be compared, or the perpendicular from the nasion 
(supposing that point is preferred), must be of the same length in all the series— 
without altering the shape of any one skull, or the relation of its parts to one 
another in position or size; which is easily done by means of proportional com- 
passes. 
Then tracings are made of each of the skull-outlines thus assimilated in the 
height of glabella or nasion above the basi-alveolar line, and they are placed over 
each other so that the basi-alveolar line in each shall coincide in position, and so 
that the perpendicular drawn thereto from the glabella or from the nasion shall 
entirely coincide. 
Top views or plans must be made by drawing outlines projected upon a plane 
parallel to the basi-alveolar line, and end views upon a plane perpendicular to the 
basi-alveolar line. 
As the result of such treatment the author exhibited outlines of two species of 
Orang, Simia satyrus and Simia morio, which were by this method clearly seen to 
illustrate the law that a diminished prognathism was accompanied by increased 
cranial development. The same truth was illustrated by profiles of skulls of a 
chimpanzee and a gorilla superposed ; by those of two chimpanzees superposed ; by 
outlines of a Fijian and an Australian skull superposed. 
The author further applied the method by the superposition of an orang’s skull- 
outline over the outline of the skull of an Andamanese, and contrived intermediate 
stages of jaw-reduction and cranium-expansion so as to indicate the type of the 
ancestral forms of the Andamanese skull. Without alleging that the ancestors of the 
