Euplankton 



Animal components of the Plankton (q. v.). 



Euploid 



Refers to the presence of a regular number of chromo- 

 somes, a multiple of the Haploid number, cf. Aneuploid. 



Euroky 



The capacity of an organism to live under a wide range 

 of environmental conditions, syn. Eurytopic. cf. Ecological 

 amplitude, steno-. 



Eurytopic 



See Euroky. 



Euthenics 



The study dealing with the improvement of living con- 

 ditions in order to secure better human beings, cf. Eugenics. 



Eufrophic 



Refers to bodies of water, accumulations of peat, etc., 

 which are rich in mineral nutrients and organic materials, 

 therefore productive. Oxygen may be deficient seasonally in 

 lakes or ponds, cf. Oligotrophic, Dystrophic. 



Evaporative Power of the Air 



The environmental factor complex including factors such 

 as temperature, relative humidity, and wind that influence 

 the evaporation of water from organisms and from other 

 bodies containing water. 



Evaporimeter 



An instrument to measure the Evaporative power of the 

 air such as an open pan of water or an Atmometer (q. v.). 



Evapotranspiration 



The sum total of water lost from the land by evaporation 

 and plant Transpiration. 



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