154 FROM FISH TO PHILOSOPHER 



aggerated. There is no evidence, and it is highly im- 

 probable, that the camel 'stores' water in either its 

 stomach or its hump. The stomach in all ruminants is 

 a complex series of chambers in which food is stored 

 before regurgitation for chewing of the cud, and in 

 which bacterial decomposition can aid in the digestion 

 of hard grasses. Misinterpretation of the presence of di- 

 gestive juices in these chambers is responsible for the 

 stomach water-storage legend. The camel's hump is, 

 however, a large reservoir of solid fat which, by com- 

 bustion, can yield twenty to thirty pounds of water. The 

 water required for urine is reduced by subsistence on 

 carbohydrate-rich, protein-poor food, since there is less 

 nitrogen demanding water for its excretion; and if food 

 is scarce, the animal's water requirement will increase 

 because of the deficiency of metabolic water, while 

 working will, of course, further cut down its endurance. 

 In midsummer, and with even moderate marching, eight 

 days without water is probably close to the camel's limit. 

 It has been said that the camel can drink 'salt water/ 

 which man and horses cannot drink, but this does not 

 imply that they can drink undiluted sea water— travelers 

 frequently call brackish water 'salt' even though the salt 

 content is fairly low from the point of view of over-aU 

 water economy, and such reports must be taken cau- 

 tiously. The camel is said to eat plants no matter how 

 spiny, and to prefer some of the more thorny shrubs to 

 others which are unarmed but which may be bitter or 

 nauseating— a tale more credible than most of the camel 

 legends. One notable adaptation of the camel is that 

 when exposed to the hot sun the body temperature in- 

 creases by as much as 12° F., thus substantially reduc- 

 ing the water lost through the skin and respiratory tract. 

 In warm weather cattle require water, but sheep can 

 remain in pasture without drinking for weeks— though 

 watering improves their growth; and in the great Aus- 

 tralian desert, where much of the land is devoted to 

 sheep raising, the animals must be watered from artesian 



