432 



INDEX. 



Hibernation (Lat. hyems, winter), 

 the torpid state of animals during 

 winter, 402. 



Histolog'ical (Gr. 'HTTOQ, a tissue ; 

 Xoyog, discourse), the doctrine 

 of the tissues which enter into 

 the formation of an animal and 

 its different organs, 210. 



Holothu v rians, soft sea slugs, biche- 

 le-mar, xxiii. 



Homaronotusde]phinoceph'alus,6G5 



Homogeneous, uniform in kind. 



Hom'ologue (Gr. bftoc, like ; Xoyog, 

 speech), the same organ in dif- 

 ferent animals under every variety 

 of form and function. 



Homol'ogy, or affinity, 16. 



Homop'tera (Gr. 6/^o, like ; irre pov, 

 a wing), the insects in which the 

 four 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. i>8a.Tig, a vesicle), a 

 bladder of albuminous membrane, 

 containing serous fluid ; generally 

 detached ; sometimes with an or- 

 ganised head and neck. 



Hy N dra (Gr. iidpa, a water-serpent), 

 the modern generic name of fresh- 

 water polyps. 



HyVlriform, similarly-formed polyps. 



Hy^drogen (Gr. vdwp, water ; 

 yei'j'dw, I produce ;) a gas which 

 is one of the constituents of 

 water. 



HyMroids, fresh-water polyps, xxiii. 



Hydrozo x a (Gr. vdpa, water ; Z&ov, 

 animal), the class of Polypi or- 

 ganised like the Hydra. 



Hymenop'tera (Gr. vfirjv, a mem- 

 brane ; TTTfpoi',' a wing,) the 

 order of insects, including the 

 bee, wasp, &c. which have foul- 

 membranous wings. 



Ichthyosaurus (ixOvf, a fish; 



a lizard), an extinct saurian, 673. 



Ide, ida3 (Gr. n'dot;, resemblance), 

 a termination indicating likeness. 

 As Acarus, a mite ; Acarida, 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'mm, the, 263. 



Imbricated (Lat. imbricatus, tiled), 

 scales which lie one upon another 

 like tiles. 



Inanimate beings, plants, 75. 



Incesso v res, perching birds, like 

 birds of prey, xxi. 



Inci x 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 x 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. 



Iuterambula 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 x ta (Lat. in, used in com- 

 position to signify not, like un; 



