286 The Increase in the Number of Erythrocytes with Altitude 
It is of further interest to determine the degree of relationship between the 
first and second counts and from this obtain an abbreviated expression giving the 
mean value of a second count as determined from the first for a given altitude. 
This we believe should have besides a purely scientific interest, one which is of 
therapeutic value ; for it may enable us to determine how far the increase of 
erythrocytes is likely to occur in anaemic individuals, and furthermore whether 
the consequent improvement in their condition is or is not counterbalanced by the 
additional requirements and strain of high altitudes. 
Fig. 4. Total First Counts with the omission of Persons suffering 
from Anaemia, or Enlarged Spleens, and Persons from High 
Altitudes. 
26 _ 
25_ 
24 _ 
23_ 
22_ 
21 _ 
20_ 
19_ 
18_ 
17_ 
16_ 
15_ 
14_ 
13_ 
12_ 
11. 
10. 
9_ 
8_ 
7_ 
6_ 
5_ 
4_ 
3_ 
2_ 
1_ 
0 1 I I I 1 I I I I 
4 0 4-5 5-0 5-5 60 6-5 7 0 7-5 
Erythrocytes in Millions. 
