432 Variation and Correlation of Skull Measurements 
change being the better correlated. The high correlation between the 
length of the skull and the zygomatic width means a regular enlarge- 
men in the transverse diameter associated with a change in length. The 
correlation between the length of the entire skull and width (squamosal 
distance) and height is comparatively low in both sexes. Therefore it is 
concluded that change in both width and height of the cranium corre- 
sponding to the change in the length of the entire skull is less regular 
than in the other three characters already discussed. It is of interest 
to note that although the correlations between the length of the entire 
skull and the width and height of the cranium are not high, yet the corre- 
lation between the width and height of the cranium is high, especially in 
the male. (See Table V.) 
(b) Correlation between the height, length, and width of the cranium. 
—Table V shows the coefficients of correlation between the three linear 
measurements just mentioned. 
TABLE V. 
Male. Female. Difference. 
Fronto-occipital length and squa- 
MOSAlACIStAanNCel Faraciyeeie kone aeee .665 + .052 .397 + .080 .268 + .095 
Fronto-occipital length and height of 
STU Wiascretet ae venovevavelies sus iel aversion shane ote bal a= .063 387 + .080 184 + .102 
Squamosal distance and height of 
Sicilia oreictoe aa eee eter -707 + .046 425 == .077 .282 + .090 
As the table indicates the width (squamosal distance) and height of the 
cranium give the highest correlation in both male and female, the length 
and width come next, while length and height give the lowest correlation. 
Although in every case the male sex gives the higher correlation, the com- 
parison between the differences and probable errors shows that we can not 
lay much weight on this apparent superiority, except in the case of the 
height and width, since in the two other cases the differences are smaller 
than three times the probable error. For comparison there are no data 
available except the observation by Pearson and Lee, o1, on the human 
skull, their results are given in Table VI. 
TABLE VI. 
Male. Female. 
Neneth and breadthie yes. German ae ke ae .286 + .062 488 + .052 
(MIN Onset ee .432 + .059 BY se AU 
Leseih and heieht 100.00 German Pees Aaot —.098 + .067 .o14 + .061 
AGN Ove eee -501 + .054 .849 + .075 
Breadth and ‘height. :..7... ee Dentecers O71 + .067 276 + .063 
NIT OW caccleushucsie cies 845 + .064 178 + .082 
