109 
by the sum of the length and the breadth of the head. This may 
appear from the following table, in which the eastern and the 
western-provinces are ranged side by side. 
Noord-Holland 343 Groningen 348 
Zuid-Holland 343.5 Drenthe 347.6 
Utrecht 343.5 Overijsel 347.3 
Zeeland 344.4 Limburg 346.2 
To the second series might be added the Achterhoek of Gelder- 
land with an average of 346.2. 
In my opinion the contrast between the two series is too regular 
for not having any significance. On looking for any connection with 
the ethnological elements of our population, it appears that the 
average is smaller, where the Frisian element is represented, while 
the Saxon element has a higher average, In this respect the diffe- 
rence between the population of Friesland (344 mm) and Groningen 
(348 mm.) is very evident. 
From the following table it appears that the breadth as well as 
the length of the head of the eastern population exceeds those of 
the western population. 
Average breadth of the head. 
Groningen 192 Friesland 190.6 
Drenthe 192 N.-Holland 190.— 
Overijsel 191.4 Z.-Holland 191.2 
Utrecht 190.3 
Averaye length of the head. 
Groningen 156 Friesland 153.4 
Drenthe 155.6 N.-Holland 153. 
Overijsel 155.9 Z.-Holland 152.3 
Utrecht 153.2 
Though both the dimensions of the north-eastern population are 
larger, the difference between the breadths is greater than that of the 
lengths. Consequently the people living in the east of our country 
have rounder heads and a greater Index cephalicus than those 
living in the western provinces. 
The last question to be answered is: how does the population of 
the two large towns stand in proportion to the people living in 
the country, surrounding these towns, with reference to the absolute 
measurements ? 
Concerning Amsterdam, the following averages were fixed: Length 
of the head 191.5, breadth of the head 151.3. 
On comparing these numbers with those of the province of N.- 
