GLOSSARY 



693 



In'tra-cer'lu-lar (L. intra, within; celluhi, 

 cells). Within cells. 



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

 cipere, to receive). Growth by the ad- 

 dition of new materials within proto- 

 plasm. 



In-vag'i-nate (L. in, in; vobina, sheath). An 

 inpushing of a cellular layer into a 

 cavity. 



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

 An animal without a vertebral column. 



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

 rolling or turning inward of cells over 

 a rim. 



Ir'ri-ta-bir'i-ty ( L. irrito, excite ) . Ability to 

 respond to a stimulus. 



Is'chi-um (Gr. ischion, hip). The posterior 

 ventral bone of the pelvic girdle. 



rso-ton"ic (Gr. isos, equal; tonikos, 

 strength). Having the same osmotic 

 pressure. 



Je-ju'num (L. jejunus, empty). The diges- 

 tive tract lying between the duodenum 

 and the ileum. 



Jug'u-lar (L. jugulum, collar bone). Per- 

 taining to the neck (jugular vein). 



Kid'ney. The major excretory organ in ver- 

 tebrates. 



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



Lab'y-rinth (Gr. labnjs, double ax). Part 

 of the inner ear in higher vertebrates, 

 composed of semicircular canals, utri- 

 culus, sacculus, and cochlea. 



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

 tears. 



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

 also referring to lymph vessels in the 

 small intestine. 



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

 hollow, or cavity, as in bone or carti- 

 lage. 



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



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

 free-living stage of an animal. 



Lar'ynx (Gr. larynx, larynx). A structure 

 containing the vocal cords located at 

 the top of the trachea and below the 

 root of the tongue in all vertebrates ex- 

 cept birds. 



Lat'er-al ( L. latiis, side ) . Toward the side. 



Le'thal gene (L. lethiim, death). A gene 

 capable of bringing about the death of 

 the organism. 



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

 A white blood cell. 



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

 tough, fibrous band of connective tis- 

 sue. 



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

 the tongue. 



Link'age (M.E. linke). Phenomenon occur- 

 ring when a series of genes are passed 

 on as a unit. 



Li'pase (Gr. lipos, fat). Fat-splitting en- 

 zyme. 



Lip'id (Gr. lipos, fat). Pertaining to fat. 



Lum'bar (L. lumbtis, loin). Pertaining to 

 the region of the back between the 

 thorax and the pelvis. 



Lu'men ( L. cavity). The internal cavity 

 within a structure. 



Lu'mi-nes"cence. The property of giving off 

 light by cells. 



Lymph (L. lympha, water). Fluid found 

 in the lymph vessels containing fat, 

 white blood cells, and plasma. 



Mac'ro-nu"cle-us (Gr. makros, large; L. 

 nucleus, kernel). The large nucleus of 

 a ciliate ( such as paramecium ) as dis- 

 tinguished from the micronucleus. 



Ma-Ia'ri-a (L. mal, bad; aria, air). An in- 

 fectious disease caused by Protozoa 

 (sporozoa) and transmitted by certain 

 mosquitos. 



Man'di-ble (L. mandere, to chew). The 

 lower jawbone in vertebrates or either 

 jaw in arthropods. 



Man'tle (L. mantellum, cloak). A sheet- 



