Tropholloxts 



The exchange of food, or the interchange of a stimulus 

 response concerning food, between animals, especially in the 

 social insects. 



Tropical Cyclone 



See Hurricane. 



Tropical Life Zone 



The portion of Central America south of the Austral 

 life zone (q. v.), bounded on the north by an accumulation 

 of temperatures during the growing season above 43 F. of 

 26,000F. cf. Life zone. 



Tropics 



The Tropic of Cancer, 2327' north latitude, and the 

 Tropic of Capricorn, 2327 / south latitude; or the region 

 between these parallels. 



Tropism 



The curvature response of an organ to a stimulus, e.g., 

 a stem growing towards a source of light and roots away from 

 the light. 



Tropoparasite 



An Obligate parasite (q. v.) that regularly lives as a non- 

 parasite during part of its life cycle. 



Tropopause 



The uppermost portion of the Troposphere (q. v.). 



Tropophyte 



A plant that can live under moist conditions pan of the 

 year and under dry conditions during another part, e.g., 

 woody plants that lose their leaves during the dry parts of 

 the year or during winter. 



Troposphere 



The part of the atmosphere extending upward about 



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