376 THE FUTURE OF ARID LANDS 
to walk and at what speed, what load he carries, what feed he 
eats and its water content, what grazing he can do, etc. It is 
therefore meaningless to discuss whether a camel can go for 5 
days or 10 days without water; as we have seen he can go entirely 
without water in the winter. 
Drinking Capacity 
When the camel drinks he fills up with water in a short time. 
On one occasion a camel that weighed 325 kg (when dehydrated) 
drank 103 liters of water in less than 10 minutes. The water be- 
comes evenly distributed in the body in less than two days. The 
blood and tissue fluids become rapidly diluted to an extent that 
would not be tolerated by other mammals, which would die from 
water intoxication at a much lower water intake. This difference 
poses a number of important physiological questions that are 
being further investigated. 
One important observation is that the camel, as well as the 
donkey, drinks an amount of water corresponding to the amount 
of water depletion, but they do not drink more than that needed 
to bring the water content of the body back to normal. In other 
words, there is no extra intake of water that could be regarded 
as a storage, or a supply to be drawn on when need arises. 
The legendary structure of the camel’s stomach, which as early 
as in Pliny’s Historia Naturalis was interpreted as serving water 
storage, serves no such purpose. When carefully examined it 1s 
clear that such a function would be extremely unlikely. The 
glandular rumen sacs that are supposed to hold the water, could 
not possibly store a significant amount. Furthermore, they con- 
tain more solid food than the major part of the rumen, and the 
fluid which can be obtained from them has the same salt concen- 
tration as the general body fluids. However, this does not contra- 
dict the widespread tale that an Arab in an emergency will kill 
his camel and drink the fluid in the stomach. The fluid would 
serve well in an emergency, and one finds abundant amounts of 
fluid in the rumen of the camel, just as in other ruminants. The 
mistake is made in implying that it 1s stored water. 
