GLOSSARY 



501 



Glochidium, pi. -a, the larva of a Fresh- 

 water Mussel. 



Glottis (the Greek name), the opening- of the 

 windpipe in the floor of the pharynx. 



Gonophore (Gk. go>ids^ offspring- ; ph^rd, I 

 bear), in Zoophytes, a bud in which egg"- 

 cells or sperms are produced. 



Green glands. See Antenjtary ^land. 



Grey matter, that part of the central nervous 

 system made up larg;ely of nerve-cells. 



Ground-Pearl, in some Scale-Insects, the en- 

 cysted underg-round pupa. 



Gular (L, gula^ the throat), near the throat. 



Gut, the dlg-estive tube or alimentary canal. 



Haemoglobin (Gk. haima, blood ; globin, a 

 kind of albuminoid), a complex substance to 

 which red corpuscles owe their colour, and 

 which in some animals may be dissolved in 

 the blood-plasma. Acts as an oxyg"en- 

 carrier, 



Halteres {L. for club-shaped weights used by 

 gymnasts). See Balancers, 



Haptic (Gk. haptikos^ endowed with the sense 

 of touch), used of sensations of contact. 



Herbivorous, plant-eating;. 



Heredity, the transmission of characters from 

 one generation to another. 



Heterocercal (Gk. h^l^ros, diverse; k^fkds, 

 tail), unsymmetrical. Used of the tail-fin of 

 certain Fishes, e.g. Sharks. 



Heterodactylous (Gk. hSt^rds^ different; dak- 

 tyWsy a toe), in the feet of some climbing" 

 Birds, with the first and second toes turned 

 back, while the third and fourth are directed 

 forwards. 



Hind-gut, the hinder part of the digestive 

 tube, developed as an inpushing- from the 

 exterior. 



Hip-girdle, the skeleton of the hip-region. 



Histology (Gk. hisf^s, a texture ; logos, a dis- 

 course), or Minute anatomy, the study of 

 structure by means of the compound micro- 

 scope. 



Hock, in hind-limb of Horse, &c., the ankle. 



Holarctic (Gk. holds, all; arkttjs, the north), 

 native to the colder parts of the Northern 

 Hemisphere. 



Homocercal (Gk. kd?7zdsy like ; kerkds, a tail), 

 applied to the lobed and externally sym- 

 metrical tail of ordinary Fishes. 



Homologous, displaying homolog-y. 



Homology (Gk. kdmd/dgds, ag;reeing), applied 

 to parts which resemble one another as re- 

 gards relative position and mode of develop- 

 ment, irrespective of use or function. Serial 

 homology, agreement between structures 

 forming a series, e.g. spinal nerves. See 

 also Analogy. 



Honey-comb stomach. See Reticiihim. 



Host, an organism on which a parasite preys. 

 See Parasitism. 



Humeral, related to the upper arm. 

 Vol. IV. 



Humerus (the Latin name), the upper-arm 



bone. 

 Hybernation, the habit of passing into a torpid 



state during the cold or dry season. 

 Hybrid (L. hyhrida, a cross-bred animal), a 



cross between two distinct species. Hybrids 



are usually sterile. 

 Hydroid Zoophytes, colonial Ccelenterates 



which in fixed stage superficially resemble 



sea-weeds. 

 Hyoid bone, supports root of tongue in higher 



Vertebrates. 

 Hyomandibular, related to the first two 



visceral arches (which see), respectively 



known as mandibular and hyoid. 



Ilium, the dorsal element of the hip-girdle. 



Imago, pi. -ines (L. for figure, portrait, or 

 statue), in Insects, the adult stage. 



Incisor, one of the front teeth of a Mammal. 

 Next to these are the Canines. See Canijie. 



Inhalent. See Siphon. 



Insertion of a muscle, the end attached to 

 a relatively movable part. 



Instinct, the power of performing complex 

 actions, subserving adjustment to surround- 

 ings, independently of experience or instruc- 

 tion. 



Integropalliate, in the shell of a Bivalve Mol- 

 lusc, with continuous pallial line. 



Intelligence, the ability to profit by experience 

 in adjusting behaviour to changing surround- 

 ings. 



Interambulacral area, in Echinoderms, a band 

 or zone which does not bear tube-feet. 



Inter - clavicle, a skeletal element situated 

 between the clavicle:i in some animals. 



Intermedium, a proximal median element in 

 the carpus or tarsus. 



Interradial, in radially symmetrical animals, 

 relating; to an interradius. 



Interradius, in radially' symmetrical animals, 

 a reg'ion of the body coming between two of 

 the radii. 



Invertebrate, devoid of a backbone or its 

 equivalent. 



Iris (L. for rainbow), the coloured part of the 

 eye, serving as a diaphragm external to the 

 lens. Its opening is the pupil. 



Ischium, the ventral and posterior element of 

 the hip-girdle. 



Isinglass, a fine kind of gelatine, prepared 

 from the swim-bladders of fishes, especially 

 sturgeons. 



Joint-gill, in Crustaceans, a gill attached to 

 the joint at the base of a limb. 



Kainozoic epoch, (Gk. kaindsy recent; soc^ 



life), the latest geological era. 

 Katabolic, relating to katabolism. 

 Katabolism (Gk. katabolc, a casting down), 



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