Elementary Species 



See Ecotype. 



Elfin Forest 



See Krummholz. 



Eltonian Pyramid 



See Pyramid of numbers. 



Eluvial Layer 



See A horizon. 



Eluviation 



The removal of material from a soil horizon by down- 

 ward or lateral movement in solution and to a lesser degree 

 in colloidal suspension, cf. Illuviation. 



Emasculation 



In plants the removal of anthers or flowers bearing sta- 

 mens to prevent self-pollination. In animals the removal of 

 sperm-producing organs. 



Embryo Sac 



The structure within the ovule of a flowering plant, in 

 which Fertilization occurs. 



Emigration 



The Migration of an organism out of a locality, usually 

 without the probability of returning, cf. Immigration. 



Encinal 



A grove or forest of evergreen oaks. 



Enclosure 



An area fenced to include certain kinds of animals, cf. 

 Exclosure, 



Encystment 



The state of inactivity of an organism in which it is sur- 

 rounded in a protective case; metabolism is reduced, resist- 

 ance to unfavorable environmental conditions increased. 



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