386 
rOPULAn SCIENCE EEYIEW. 
ill its adult state, as a cylinder much modified and distorted. At 
an early embryonic period it is in all animals curved remark- 
ably downwards on itself. Examining it, however, in adults, 
the total curvation of the cranial cylinder is seen to differ much 
in different species, becoming greater the higher the position of 
the animal. This increasing curvature is accompanied with 
increasing expansion of the roof bones of the skull and arrest of 
the basal hones: thus in the human subject the roof bones are 
expanded far more than in any other animal, while the basal 
hones are crowded and even fused together by their position in 
the concavity of the curve of the cylinder. The human curve is 
not complete in infancy ; for, as the present writer has else- 
where shown, it goes on increasing for several years after birth : 
it is also greater in the higher than in the lower races of man- 
kind. This curvature is an important means of increasing the 
space for the cerebral hemispheres, by lengthening the roof ; 
and it does so most effectually when accompanied with the 
other means which Nature uses to expand the cranium, namely, 
increase of vertical and transverse diameter of the cylinder. 
Further, before returning to the question of foreheads, it must 
l)e pointed out that the position in which the head is articulated 
with the neck differs in different persons, according to the 
weight of the fore and back parts, so as to preserve balance. 
This is best seen in the process of growth, for the forehead and 
face have the smallest proportional development in young 
diildren ; and as they become large, the head is tilted further 
and further round on the top of the vertebral column, so as to 
throw more weight behind the point of support, to balance the 
weight in front : and this tilting takes place to a much greater 
extent in men than in women, because in women the face and 
forehead remain proportionally lighter. 
From the foregoing considerations it must be apparent to 
everyone that loftiness of forehead results from general height 
of the whole skull, and that the apparent form of the forehead 
is very dependent both on the amount of total cranial curvature 
and on the balance of the head on the vertebral column. The 
deceptiveness of mere general appearance may, perhaps, be best 
illustrated by noting how people speak of the large foreheads of 
children. The frontal eminences of the child project forwards, 
and the head arches boldly above them, giving the appearance 
of a large forehead ; but, in point of fact, the forehead of the 
child is proportionally very small and undeveloped; and its 
apparent prominence is due partly to the shallowness of the 
orbits, giving a comparative prominence to the frontal emi- 
nences, and partly to the wliole skull being so set on the top of 
the spine that the forehead and face bones are turned more 
downwards than in the adult. The arch of the upper part of 
