Shinkishi Hatai 427 
width of the cranium or squamosal distance and in the fronto-occipital 
length where they are nearly alike in the two sexes. Generally speaking 
the changes associated with the increase in the length of the entire skull 
are relatively greater in female than in male. This is especially evident in 
the length and width of the cranium and the zygomatic width, although 
the absolute amount of change is considerably less in the female than in 
the male. In the female the relative change is very slightly greater in the 
nasal bone and is the same in the height of the skull. The same table 
TABLE II. 
Male. | Female. 
‘Minimum | Mean * /Maximum | Maximum | Mean * | Minimum 
= | mm. mm. mm, mm, | mm. | mm. 
Length of theentireskull. 39.4 43.3 47.4 | 44.5 | 41.5 38.9 
Rate 100 100 100. | 100. | 100. 100. 
Zygomatic width. 19.6 21.7 24.8 | 23.4 | 20.9 18.9 
Rate 49.8 50.2 52 52.5 | 50.3 48.5 
Length of the nasal bone. | 14.7 17.0 18.7 17.8 |15.7 14.4 
Rate | 37.3 | 39.2 39.3 40.0 | 37.7 37.0 
Fronto-occipital length. | 24.9 |27.8 28.8 28.2 26.4 24.9 
Rate | 63.2 63.0 | 60.7 63.3 63.5 64.0 
Squamosal distance. 14.6 15.3 16.2 16.2 }15.1 14.4 
Rate 37.0 | 35.8) 841 36.4 | 36.2| 37.0 
Height of Skull. | 10.4 11.5 13.0 12.2 | ileal 10.3 
Rate | 26.4 26.5 27.4 | 27.4 | 26.8 26.4 
shows us clearly that in respect to the length of the entire skull, the width 
and length of the cranium are greater in female than in male although in 
both sexes the absolute amount of change is less than for any other 
characters measured. The relatively slight increase in the width of the 
skull (zygomatic width) associated with the increase in the length of the 
entire skull, has also been noticed by Allen, 94, in the case of Neotoma 
micropus. 
When the mean values (Table II) are treated in the same manner as 
the two extremes, additional light is thrown on the changes following the 
increase in the length of the entire skull. In all characters, except the 
* Taken from Table I. 
