Antibody 



A substance such as Antitoxin produced in an animal 

 when foreign material (Antigen) is introduced into the body. 

 The antibody counteracts the effect of the antigen. 



Anticline 



A geological structure or arch formed by strata from 

 opposite sides dipping upward toward a common line. cf. 

 Syncline. 



Anticryptic 



Refers to coloration which facilitates aggressive action 

 of an animal. 



Anticyclone 



A mass of air of high atmospheric pressure compared to 

 adjacent areas, in which the circulation of the air is clock- 

 wise in the northern hemisphere, anti-clockwise in the 

 southern hemisphere. 



Antigen 



Parasites, substances produced by them, enzymes, toxins, 

 or proteins which cause the formation of antibodies in the 

 body of an animal. 



Antitoxin 



An Antibody (q. v.) that counteracts a Toxin (q. v.), e.g., 

 antitoxin serum used in treatment of diphtheria. 



Apatetic 



The coloration of an animal that causes it to resemble 

 physical features of the habitat. 



Aperiodicity 



The irregular occurrence of phenomena, cf. Periodicity. 



Apetalous 



Refers to flowers that lack petals. 



27 



