III. GLOSSARY 



A.BIOGENESIS. The abandoned idea that living matter may arise 

 from non-living without the influence of the former. See Bio- 

 genesis. 



ABSORPTION. The passage of nutritive and other fluids into living 

 cells. 



ACOELOMATE. Not possessing a coelom, or body cavity. E.g., Hydra. 



ACQUIRED CHARACTER. A modification of body structure or func- 

 tion which arises during individual life as a result of environ- 

 mental influences. 



ADAPTATION. The reciprocal fitness of organism and environment; 

 a structure or reaction fitted for a special environment; the 

 process by which an organism becomes fitted to its surroundings. 



ADRENALS. Suprarenal bodies. Ductless glands situated near 

 the kidneys. Secretion supplies a hormone known as adrenin. 



ADVENTITIOUS. Not in the usual position, e.g., aerial roots. 



AEROBE. An organism requiring free oxygen. See Anaerobe. 



AFFERENT ROOT. Dorsal, or posterior, root of certain cranial and 

 all spinal nerves through which sensory nerve impulses enter the 

 brain and spinal cord. See Efferent Root. 



ALGAE. A heterogeneous group of lower plants in which the body 

 is unicellular or consists of a thallus; e.g., Sphaerella, Spirogyra, 

 Seaweeds. 



ALIMENTARY CANAL. The digestive tract. 



ALLELOMORPHS. Genes similarly situated on homologous chromo- 

 somes which produce ' alternative,' or ' contrasting/ characters. 



ALTERNATIVE INHERITANCE. Typical .Mendelian inheritance. 



AMINO ACID. Components of proteins. Organic acids in which one 

 hydrogen atom is replaced by the amino group (NH 2 ). Mono- 

 amino acids, e.g., Glycine (CH 2 NH 2 .COOH). Diamino acids, 

 e.g., Lysine (H 2 NCH 2 .CH 2 .CH 2 .CH 2 .CHNH 2 .COOH). 



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