S22 CHIKANOSUKE OGAWA 
DIAMETER AND LENGTH OF ALVEOLAR DUCTS 
I mean by the term diameter the distance between the edges 
of two opposite alveolar septa, and by the term length, the length 
of each branch of the alveolar ducts. By thus measuring both 
I intend to show how frequently the bifurcations in alveolar 
ducts take place. 
TABLE 1 
LENGTH DIAMETER 
Millimeters Number of times Millimeters. Number of times. 
0.08 1 0.11 1 
0.16 1 0.12 1 
OnLy 3 0.16 it} 
0.18 1 0.17 2 
0.20 2 0.19 1 
0.24 1 0.20 2 
0.25 3 0.21 1 
0.26 1 0.23 1 
0.30 4 0.24 il 
0.31 4 0.25 1l7/ 
0.32 i 0.26 2, 
0.35 4 0.27 1 
0.36 i 0.28 1 
0.37 Z 0.30 7 
0.38 1 ——_ >. tan 
0.40 2 Ave. 0.24 Total 39 
0.42 1 
0.44 1 
0.45 3 
0.50 2 
Ave. 0.32 Total 40 
A branch of alveolar ducts is not always thicker than the 
branches of the next order. In other words, on division the 
decrease in the diameter of the alveolar ducts is not marked. 
Schulze puts the diameter of alveolar ducts from 0.4 mm. to 
0.2 mm., Kolliker gives the average of 0.27 mm. 
