Escarpment 



A long, inland cliff or steep slope, usually high, formed 

 by erosion or possibly by faulting, syn. scarp. 



Esker 



A long, narrow ridge of gravel and sand deposited by a 

 stream flowing under or within a glacier, cf. Kame. 



Esophagous (Oesophagous) 



The portion of the alimentary tract between the pharynx 

 and the stomach. 



Espinal 



A thorny woodland. 



Essential Element 



A chemical element required by green plants for normal 

 growth, such as the primary essential elements: hydrogen, 

 oxygen, nitrogen, phosphorus, and potassium; secondary 

 essential elements: sulfur, calcium, and magnesium; and the 

 trace or minor elements: iron, boron, manganese, copper, 

 zinc, and molybdenum. The last six, and traces of other 

 elements, are required in only minute quantities. 



Establishment 



The successful growth of an organism in a new location, 

 syn. Ecesis. cf. Invasion, Spread, Dispersal. 



Estival 



Refers to the summer season, cf. Aspection. 



Estivation 



The condition in which an organism may pass the sum- 

 mer and in which its normal activities are greatly curtailed 

 or temporarily suspended, cf. Dormancy, Hibernation. 



Estuary 



An arm of the sea at the mouth of a river, in which the 

 current of the river meets the tide. 



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