Acldotrophic 



Refers to organisms that feed on food having an acid 

 reaction. 



Acquired Character 



A modification of structure or function appearing during 

 the lifetime of an individual, caused by environmental con- 

 ditions, e.g., broad leaves of some plants growing in shade. 



Acre-Foot 



The quantity of water that will cover one acre one 

 foot deep. 



Acre-Inch 



The quantity of water that will cover one acre one 

 inch deep. 



Acrodomatia 



Structures on plants that shelter mites. 



Acropetal 



Refers to the development of organs in plants, the oldest 

 at the base, the youngest at the tip. cf. Basipetal. 



Acrophytia 



Plant communities in alpine regions. 



Actic 



Refers to the part of the seashore between tide marks. 

 See Littoral. 



Actinometer 



An instrument which measures radiant energy, especially 

 the property that produces chemical effects. 



Actinometry 



The measurement of chemical reactions caused by 

 radiation. 



Actinomycetes 



A group of organisms possessing very fine hyphae or 



