432 



INDEX. 



Hibernation (Lat. hyems, winter), 

 the torpid state of animals during 

 winter, 40'Z. 



Histolog'ical (Gr. IOTOC, a tissue ; 

 Xoyog, discourse), the doctrine 

 of the tissues which enter into 

 the formation of an animal and 

 its different organs, 210. 



HolothuVians, soft sea slugs, biche- 

 le-mar, xxiii. 



Homal'onotus delphinoceph'alus,665 



Homoge'neous, uniform in kind. 



Hom'ologue (Gr. 6/xoc, like ; Aoyoe, 

 speech), the same organ in dif- 

 ferent animals under every variety 

 of form and function. 



Honiorogy, or affinity, 16. 



Homop'tera (Gr. oftog, like ; ir-tpov, 

 a wing), the insects in which the 

 fuur wings have a similar struc- 

 ture, but restricted in its applica- 

 tion to a section of Hemiptera. 



Hu'merus, or shoulder-bone, the, 272. 



Hy'aline (Gr. vaXoc, crystal) matter, 

 the pellucid substance which de- 

 termines the spontaneous fission 

 of cells, 42. 



Ilydat'id (Gr. iiSanc;, a vesicle), a 

 bladder of albuminous membrane, 

 containing serous fluid ; generally 

 detached ; sometimes with an or- 

 ganised head and neck. 



Hy'dra (Gr. vBpa, a water-serpent), 

 the modern generic name of fresh- 

 water polyps. 



HyVlriform, similarly-formed polyps. 



Hy x drogen (Gr. vSwp, water ; 

 ye wa.w, I produce ;) a gas which 

 is one of the constituents of 

 water. 



Hy'droids, fresh-water polyps, xxiii. 



Hydrozo v a (Gr. vdpa, water ; %u>ov, 

 animal), the class of Polypi or- 

 ganised like the Hydra. 



Hymenop'tera (Gr. V/JLTJV, a mem- 

 brane ; TTTtpdv,' a wing,) the 

 order of insects, including the 

 bee, wasp, &c. which have four 

 membranous wings. 



!chthyosau'rus(ix0fc, a fish; 



a lizard), an extinct saurian, 673. 



Ide, idae (Gr. tidog, resemblance), 

 a termination indicating likeness. 

 As Acarus, a mite ; Acaridas, re- 

 sembling the mite. 



Ig'neous (Lat. ignis, fire) rocks, 646. 



Iguan'odon, an extinct gigantic rep- 

 tile, resembling in its teeth the 

 iguana, an existing lizard. 



Il'ium, the. 263. 



Imbricated (Lat. imlricatus, tiled), 

 scales which lie one upon another 

 like tiles. 



Inanimate beings, plants, 75. 



Incesso'res, perching birds, like 

 birds of prey, xxi. 



Inci v sor (Lat. incido, I cut), or cut- 

 ting teeth, 341. 



IncubaHion (Lat. incubatio), hatch- 

 ing of eggs by the mother. 



Incuba v tion, 442 ; physical and che- 

 mical changes in the egg during, 

 499. 



In'cus, or anvil, the, 149. 



Infuso v ria (Lat. in/undo}, microscopic 

 animals, inhabiting infusions of ani- 

 mal or vegetable substances, xxiv- 



Infusoria, digestion in the, 314. 



Inoper'cular, univalve shells which 

 have no operculum or lid. 



Inorgan'ic, not made up of tissues. 



InsalivaHion, 345. 



In'sects, a class of the Articulates, 

 xxii. 



In'sects, digestive organs of, 327 : 

 jaws of, 337 ; circulation, 370 ; 

 respiration, 385. 



Instinct, 191204. 



Intelligence and instinct, 185 204. 



Interambula v cra, the imperforate 

 plates which occupy the intervals 

 of the perforated ones, or ambu- 

 lacra in the shells of the Echino- 

 derms ; see AMBULACRA. 



Intersti'tial (Lat. interstitium), rela- 

 ting to the intervals between parts. 



Invertebra v ta (Lat. in, used in com- 

 position to signify not, like un ; 



