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COLLEGE ZOOLOGY 



In'ter-cel"lu-lar (L. inter, between; cellula, 

 cells). Between cells. 



In-ter'nal se-cre'tion. A hormone, the product 

 of an endocrine gland. 



In"ter-phase' cell (L. inter, among, between; 

 Gr. phasis, to make to appear. L. cella, com- 

 partment). A cell that is not undergoing 

 mitotic division; a metabolic cell; the stage 

 between two mitoses. 



In-tes'tine ( L. intestinus, internal ) . Part of the 

 digestive tract posterior to the stomach. In 

 animals without a stomach, the intestine is 

 usually the digestive tract posterior to the 

 ingestive region. 



In'tra-cel'^lu-lar (L. intra, within; cellula, 

 cells). Within cells. 



In'tus-sus-cep"tion (L. intiis, within; suscipere, 

 to receive). Growth of living things accom- 

 plished by adding new materials within the 

 protoplasm. 



In-vag'i-nate (L. in, in; vagina, sheath). To 

 infold; the folding or inpushing of a layer 

 of cells into a cavity, as of a blastula to form 

 a gastrula. 



In-ver'te-brate (L. in, not; vertebra, joint). An 

 animal without a vertebrae (backbone). 

 Also used as an adjective, from protozoans 

 to vertebrates. 



In'vo-lu"tion (L. in, in; volvere, to roll). The 

 process of rolling or turning in of cells over 

 a rim. 



Ir'ri-ta-bir'i-ty (L. irrito, excite). The ability 

 to respond to stimuli, one of the fundamen- 

 tal characteristics of protoplasm. 



rso-ton"ic (Gr. isos, equal; tojiikos, strength). 

 In terms of a living cell, concentration of 

 water molecules is the same inside and out- 

 side the cell; therefore, the water molecules 

 pass in and out of the cell in equal numbers. 

 This results in no change in cell size. 



Jc-ju'num (L. jejunus, empty). That part of 

 the intestine extending from the duodenum 

 to the ileum in a vertebrate. 



Jug'u-lar (L. jugulum, collarbone). Pertaining 

 to the throat, as jugular vein. 



Ka-tab'o-lism. See Catabolism. 



Kid'ney. The chief organ for the excretion of 

 liquid nitrogenous wastes in vertebrates; also 

 often loosely applied to analogous organs in 

 certain other animals. 



La'bi-al (L. labium, lip) . Pertaining to the lips. 



La'bi-um (L., lip). A lip, specifically the lower 

 lip of an insect's mouth-part structures. 



La'brum (L., lip). Upper lip of the insect's 

 mouth. Dorsal to the mouth opening. 



Lac'ri-mal (L. lacrima, tear). Pertaining to 

 tears. 



Lac'te-al (L. lac, milk). Pertains to milk; 

 often refers to the lymph vessels of the small 

 intestine of a vertebrate. 



La-cu'na (L. lacuna, cavity). A small cavity 

 or space, particularly in cartilage or bone, 

 that in life contains a cartilage or bone cell. 



La-mel'la (L., small plate). A thin leaflike 

 layer. 



Lar'va (L. larva, ghost). An immature, free- 

 living stage in the life cycle of various ani- 

 mals, which reach the adult form by under- 

 going a metamorphosis. 



Lar'ynx (Gr. larynx, larynx). The organ sit- 

 uated between the trachea and the base of 

 the tongue, into which the glottis opens 

 and which contains the vocal folds. A larynx 

 is typicallv found in all lunged vertebrates 

 above fishes, except birds. 



Lat'er-al (L. latus, side) . The side of the body. 

 At each side of the median line. 



Le'thal gene (L. lethum, death. Gr. genesthai, 

 to be produced ) . A gene that is capable of 

 bringing about death. Lethal genes may be 

 either dominant or recessive and kill the 

 organism at any stage of its development. 



Leu'co-cyte (Gr. leucos, white; kytos, cell). A 

 white blood cell or corpuscle. 



Lig'a-ment (L. ligamentum, bandage). A 

 tough, fibrous band of tissue connecting 

 bones or supporting viscera. 



Lin'gual (L. lingua, tongue). Pertaining to the 

 tongue, as lingual artery. 



Link'age (M.E. linke). A tendency for certain 

 traits (characters) to stick together in 

 heredity because the genes for such traits are 

 located on the same chromosome. 



Li'pase (Gr. lipos, fat). A fat-splitting enzyme. 



Lip'oid (Gr. lipos, fat). Of fatty nature. 



Lum'bar (L. lumbus, loin). Pertaining to that 

 region usuallv known as the small of the 

 back; the region just posterior to the ribs of 

 vertebrates. 

 Lu'men (L., cavity). Internal cavity within a 

 body or structure, such as the lumen of the 

 intestine, a gland duct, or a blood vessel. 



