GLOSSARY 



691 



Ge-net'ics (Gr. gignesthai, to be born). The 

 science of heredity. 



Gen'i-tal (L. gignere, to beget). Pertain- 

 ing to the reproductive organs. 



Gen'o-type (Gr. genestliai, to be produced; 

 typos, impression). Genie constitu- 

 tion. 



Ge'nus (L. genere, to beget). Taxonomic 

 sub-division of a family. 



Ge-ot'ro-pism (Gr. ge, earth; repein, to 

 turn). Response to gravity. 



Germ lay'er (L. germen, germ). An em- 

 bryonic primary cell layer. 



Germ plasm (Gr. plasma, something 

 molded). Reproductive and hereditary 

 substance of individuals which is trans- 

 mitted in direct continuity to the germ 

 cells of succeeding generations. 



Gest-a'tion (L. gerere, to carry). The pe- 

 riod of pregnancy. 



Gill (Gr. cheilos, lip). An aquatic respira- 

 tory organ. 



Gill arches (Gr. cheilos, lip; arcus, bow). 

 The walls bearing the gills. 



Gill slit (pharyngeal cleft) (A.S. slitan). 

 Paired openings in the wall of the 

 pharynx of chordates which permits 

 the water that entered through the 

 mouth to escape externally during 

 breathing. 



Giz'zard (Fr. giser, gizzard). An enlarged 

 muscular part of the digestive tract. 



Gland (L. glans, acorn). A cell or collec- 

 tion of cells which produces a specific 

 product. 



Glo-mer'u-lus ( L. glomare, to make a ball ) . 

 A tuft or cluster of blood vessels pro- 

 jecting into the capsule of each urinif- 

 erous tubule. 



Glot'tis ( Gr. glotta, tongue ) . Opening from 

 the pharynx into the larynx. 



Gly'co-gen ( Gr. glyktis, sweet; gen, produc- 

 ing). A carbohydrate stored in many 

 parts of the body; also known as "ani- 

 mal starch." 



Go'nad (Gr. gonos, reproduction). A gam- 

 ete-producing reproductive organ. 



Go-nan'gi-um ( Gr. gone, seed; angeion, ves- 



sel). The reproductive individual of a 



hydroid colony. 

 Gre-gar'i-ous (L. gregariiis, from grex, a 



herd). The property of animals of 



flocking together. 

 Gul'let (L. gula, gullet). Esophagus. 



Hab'i-tat (L. habitare, to dwell). Environ- 

 ment of an organism. 



He'mo-coel (Gr. haima, blood; koilus, hol- 

 low). A body cavity functioning as a 

 part of the circulatory system. 



He'mo-cy"a-nin (Gr. Jwi7na, blood; kyanos, 

 a dark-blue substance ) . An oxygen-car- 

 rying pigment, copper-bearing and blue 

 in color, found in the blood of mollusks 

 and arthropods. 



He'mo-glo"bin (Gr. haima, blood; L. glo- 

 bus, globe). Oxygen-carrying red pig- 

 ment of blood. 



He'mo-phir'i-a (Gr. haima, blood; phil, to 

 love). A hereditary condition in man 

 in which blood clotting is abnormally 

 slow. 



Hap'loid ( Gr. haploos, single; eidos, form ) . 

 The reduced number of chromosomes 

 found in the gametes; half the diploid 

 number. 



He-pat'ic (Gr. hepar, liver). Pertaining to 

 the liver. 



Her-biv'o-rous (L. herha, herb; vorare, to 

 devour). Subsisting on plants. 



Her-ed'i-ty ( L. hereditas, heirship ) . Organic 

 resemblance based on descent. 



Her-maph'ro-dite ( Gr. Hermes, Aphrodite ) . 

 The possession of both male and fe- 

 male reproductive organs. 



Het'er-o-zy"gote (Gr. heteros, different; 

 zeugon, yolk). A hybrid formed from 

 gametes having different genes for the 

 same trait. 



Hi'ber-na"tion (L. hiems, winter). The dor- 

 mant state in which some animals spend 

 the winter. 



His'ta-mine. An organic compound which 

 is a powerful dilator of the capillaries 



