H. W. Acton and W. F. Harvey 
291 
Concluding Remarks. 
1. The mean of our observations is higher than that usually given for an 
erythrocyte count in a healthy individual, namely, 5,600,000 as against 5,000,000. 
2. The deviations from the mean may be considerable and yet consonant with 
apparent health. The range of our observations extended from 4,200,000 to 
7,300,000 for a random sample of a varied population. 
3. The effect of altitude is to cause a rapid increase in the erythrocyte content 
of the blood — quite apparent within a few weeks. 
4. Permanent residents at a high altitude exhibit a higher erythrocyte content 
than those dwelling at lower altitudes. 
5. Anaemic individuals do respond to the stimulus of altitude with production 
of additional erythrocytes but in very different degrees and may not do so in 
a degree sufficient to meet the requirements of a high altitude. 
37- 2 
