differ in two characters such as color of flowers and length of 

 stems, cf. Monohybrid. 



Dimorphism 



The state of organs of a plant or animal or individuals 

 in a population occurring hi two forms or colors, e. g., a 

 plant with leaves of two forms, cf. Polymorphism. 



Dinoftagellate 



A motile organism hi the class Dinophyceae of the algae; 

 great abundance of some forms ("red tides") along coasts 

 causes death of many fish. 



Dioecious 



Refers to plants with pistillate and staminate flowers in 

 separate plants, e. g. willows, cf. Monoecious. Diclinic. In 

 animals refers to unisexual organisms, cf. Hermaphrodite. 



Diploid 



Refers to the presence of chromosomes in pairs or in two 

 sets, resulting from the union of two Gametes, each with a 

 single set (Haploid, q. v.). 



Dipterous 



Refers to an insect in the order Diptera which possess 

 two wings (except parasitic forms), e. g., housefly, mosquito. 



Disclimax 



An enduring Climax (q. v.) community altered by dis- 

 turbance by man or domesticated livestock, e. g., a grassland 

 which has replaced a deciduous forest, cf. Plagioclimax. 



Discontinuity 



The existence of a gap in the geographic distribution of 

 a Taxon. cf. Distribution, Disjunct. 



Disjunct 



Refers to the absence of a connection as in the geographic 

 distribution of a Taxon or a community, cf. Discontinuity. 



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