140 
DR. J. CLELAND ON THE VARIATIONS OF THE HUMAN SKULL. 
Esquimaux skulls ; but it rises to about 180° in the German and Irish, which have 
a high proportion of arch to base-line ; and in the Kanaka, Maori, and Peruvian skulls 
it sinks to 173° and 174°. 
The deep frontal angle gets regularly larger from foetal up to adult life, as the frontal 
bone gets larger in proportion to the rest of the arch ; or, to put it differently, it may be 
said that the increasing length of the frontal bone pushes down the fore part of the 
ethmoid and bends it on the sphenoid. 
Area of the frontal, parietal, and occipital parts of the diagrammatized profile (General 
Table, columns 40 to 46). — So far as the examination of angles and of measurements of 
arch and base has gone, the present inquiry has shown no reason for the belief that 
frontal development is more important or nobler than development of the other cranial 
regions ; nor is any evidence to that effect to be got by comparing the areas of the dif- 
ferent regions. The calculation of the areas has for the sake of simplicity been made 
on the angular figures produced by joining by means of straight lines the series of points 
already enumerated as selected for measurement. Thus the area of a trapezium has 
been measured in the case of the frontal region, a pentagon in the parietal, and a hexagon 
in the occipital region. The results are therefore only approximate, but they are suffi- 
ciently accurate for practical purposes. 
It is remarkable that in the relative proportions of these three areas, no national nor 
sexual differences whatever are exhibited. Unfortunately the writer is unable to say 
how far this statement is applicable to the Chinese and Australian skulls, in which the 
parietal part of the arch was found habitually to predominate over the frontal and occi- 
pital parts ; for Lucae’s figures do not furnish sufficient details for making the calcula- 
tion in the same way as it has been done in other skulls. But on comparing the average 
area in those nationalities of which three or more specimens have been measured, viz. 
Scotch, Irish, French, German, Greek, Negro, Kafir, and Hindoo, it is found that the 
variation in the occipital area is only 1*56 per cent., in the parietal areal'19, and in the 
frontal l - 74 per cent., a result equivalent to no variation at all. This is the more 
remarkable as in the series of skulls examined, the variation among individuals in the 
occipital area reaches 11-98 per cent., in the parietal area 10-99 per cent., and in the 
frontal area G'36 per cent. The Chinese skull 85 has the smallest proportion of frontal 
area in the whole series, on account of the shallowness of its orbits, and on the same 
account the synostotically deformed skull 89 has it nearly as small. Also among those 
which have the proportion of the frontal area smallest are the two female skulls, Irish 
and Scotch, 57 & 42, in which there is no spheno-parietal contact. 
The same variability of the proportions of the three areas in individuals which is seen 
in the adult is observed also in young skulls. The figures expressing those proportions 
in the foetal and infantile skulls are almost all such as might be found in the adult ; but 
the averages show a somewhat larger proportion of parietal, and a smaller proportion of 
occipital and frontal area. The difference, however, does not seem to be such as to 
account for the obvious predominance in bulk of the parietal region in young skulls, 
which probably depends most on breadth. 
