Water 87 



Animals that are characteristic of swamps, marshes, and pools 

 often have remarkable powers of enduring desiccation. Water 

 mites stand partial desiccation, if covered with dry debris, for 

 3 to 6 months, but die quickly if exposed in air (Szalay, 1928) . 

 An oriental leech lived in a cocoon on dry paper for a week, 

 during which it lost 80% of its weight, and became active in a 

 short time when again immersed in water (Oka, 1922) . Frogs 

 and toads cannot absorb water to any extent from a moist atmos- 

 phere, but must come in contact with water, soil, or some other 

 wet object to replenish their body losses (Adolph, 1932) . Certain 

 air-breathing fishes in India live without water in moist air on wet 

 grass from 5 to 60 hours (Das, 1927) . CoUembola on account of 

 their small size are usually limited to damp habitats, but those 

 with tracheal tubes are on the whole able to stand desiccation better 

 than those without (Davies, 1928) . Certain serpent-head fishes in 

 Siam remain in dry soil in rice fields without water for as much as 

 four months in stiff mud cells (Smith, 1927) . Lung-fishes also 

 remain encapsuled in mud cocoons for as long as two years (per- 

 haps sometimes for five years) , and urea may accumulate in their 

 bodies until it amounts to as much as 2% of their body weight 

 (Smith, 1930) . According to Hubbs, some swamp fishes in North 

 America, (Eucaulia, Umbra, Amia, Ameiurus, etc.), can live for 

 a time in mud. Lung-like cavities were developed in fishes as an 

 adaptation to dry seasons, according to Romer (1945), but the 

 writer believes that such cavities more often originated in decreas- 

 ing aquatic habitats where there was a lack of oxygen. 



Land animals of course all have more or less ability to do with- 

 out water and some live their whole lives without any free water. 

 The jerboa and gazelle subsist on vegetation and will not drink if 

 water is available (Buxton, 1923) . A fasting meal-worm larva 

 (Tenebrio) can keep its body water constant for a month while 

 fasting at temperatures of 23° to 30 °C. and humidities of 0% 

 to 60%. "It seems to be able to do this by consuming some stored 



