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VIII. An In quirt/ into the Variations of the Human Skull, particularly in the Antero- 
posterior Direction. By John Cleland, M.D . , Professor of Anatomy and Physiology , 
Queens College , Galway. Communicated by Dr. Allen Thomson, F.B.S. 
Received June 15,— Read June 17, 1869. 
Contents. 
Page 
Introductory 17 
I. Cranium proper 122 
Extent of arch and base-line 122 
Regions of the base 125 
Foramen magnum 125 
Orbital length 125 
Eoramino-optic line 126 
Angles at which the three divisions of the 
base lie one to another 127 
Length of arc of different portions of the 
arch 131 
Length of chord of different portions of the 
arch 132 
Angles expressive of the form of different 
parts of the arch 134- 
Young skulls 134 
Gravitation changes 136 
National differences 137 
Deep frontal angle 139 
Area of the frontal, parietal, and occipital 
parts of the diagrammatized profile .... 140 
Distance of the arch at various points from 
the base 141 
Page 
Height 142 
Proportion of height to frontal depth 143 
Length 144 
Proportions of height and breadth to length 144 
Position of greatest breadth 148 
Radial measurements and position of the ear 149 
II. The face 152 
The orhito -nasal angle 154 
Length of face from fronto -nasal suture to 
nasal spine 156 
Naso-basilar angle and naso-basilar line . . 156 
Causes of prognathism 157 
Relations of the upper jaw to the ear .... 159 
III. Position of the skull on the vertebral co- 
lumn 160 
Applications to artistic anatomy 162 
IY. Anomalous forms of skull 164 
Unusual magnitude 164 
Hunchback 165 
Cretins and idiots 166 
Artificial deformities 167 
Y. Comparison of the human skull with the 
skulls of various animals 168 
The following investigations were commenced about nine years ago, and some of the 
results were laid before the Physiological Subsection of the British Association Meeting 
at Manchester in 1861. Circumstances, during a series of years, prevented the writer 
from elaborating so fully as he desired the results of the measurements which he had 
already made ; but this is the less to be regretted, as in the meantime he has had oppor- 
tunity of making additional measurements, and the writings of others which have from 
time to time appeared have given him additional information without interfering with 
the line of inquiry which he proposed to himself to pursue. That inquiry was com- 
menced in the belief that descriptions of crania expressing, however precisely, the 
MDCCCLXX. R 
