vegetation; essentially a cross section of the vegetation, cf. 

 Line-intercept method. Quadrat. 



Transformation 



The change of one type of bacterium to another type, 

 as when DNA from Type I of Pneumococcus is transferred 

 to Type II it replaces some of the Chromatin in the latter 

 whose characteristics such as resistance to Penicillin may 

 thus be modified. Genetic information is thus transferred. 



Transgressive 



Species that regularly occur in an upper layer in a com- 

 munity found also in a lower stratum. 



Transhumance 



The periodic and alternating movement of livestock 

 between two regions that differ in climate. 



Transient Species 



A species that migrates through a locality without breed- 

 ing or over-wintering. 



Transition Life-Zone 



The northern part of the Austral life-zone (q. v.). 



Translocation 



(1) The movement of materials in solution from one 

 part of a plant to another part. cf. Xylem, Phloem. (2) The 

 separation of a part of a Chromosome and its attachment to 

 another one. 



Transpiration 



The loss of water in vapor form from a plant, mostly 

 through the stomata and lenticels. cf. Stoma, Lenticel. 



Transpiration Coefficient 



The ratio of the oven-dry material produced by a plant 

 during a more or less extended period of time (usually the 

 entire growth period) to the total amount of water transpired 

 during the same period. 



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