CHAPTER V 



ANIMALS AND THE PHYSICAL 

 ENVIRONMENT (continued) 



i. Water Supplies, ii. Fauna of Waters in Deserts, iii. 

 Heat and Relative Humidity, iv. Animals and Wind. v. 

 Relationships with Soil. 



i. Water Supplies 



I propose to marshal some of the available facts 

 which relate to the reaction of the desert animals 

 to drought, heat, wind, and other particular ele- 

 ments in the cHmate, and to deal first with the 

 means adopted by the animals for making the 

 most of a scanty and irregular water supply. In 

 many semi-deserts and in all deserts rain falls 

 at such rare intervals that life would be impos- 

 sible to any species directly and solely dependent 

 on it, but other sources of water are available, 

 and probably on the whole more important. Per- 

 haps the most obvious is the dew. Meteorological 

 records of dew-fall are scanty from all parts of the 

 world, and observation of dew-drinking by small 

 animals are very few. Atkinson, writing of his 

 experiences at Abu Kir in Egypt, remarks : " The 

 water supply of the numerous beetles inhabiting 

 the patches of baked clay in the coastal deserts 



81 o 



