Mesosaprobic 



Refers to an aquatic environment in which the oxygen 

 content is considerably reduced and in which much decom- 

 position of organic materials is taking place, cf. Catarobic, 

 Polysaprobic. 



Mesotherm 



An organism that requires moderate warmth and mod- 

 erate moisture, e. g., corn, hickory, cf. Megatherm, Micro- 

 therm, Hekistotherm. 



Mesotrophic 



Refers to a swamp supplied with a moderate amount of 

 nutrients. 



Mesozoic 



One of the great geological eras, preceding the Cenozoic 

 era, began about 205 million years ago and lasted about 130 

 million years; divided into the Triassic, Jurassic, and Cre- 

 taceous periods. 



Metabolic Water 



The water obtained from the chemical breakdown of 

 foods by some organisms such as the clothes moth. 



Metabolism 



The sum total of chemical processes occurring within 

 an organism or a portion of it, includes Anabolism and 

 C atabolism (q.v.). Basal metabolism is the rate of expendi- 

 ture of energy while an animal is at rest. cf. Autotrophic, 

 Heterotropkic. 



Metabolite 



Any substance that plays a part, directly or indirectly, 

 in Metabolism. 



Metagenesis 



See Alternation of generations. 



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