USED IN NATURAL HISTORY. 



97 



META'BOLA. ) A term applied to 



METABO'LIAN. those genera of 

 insects which undergo metamor- 

 phosis, or pass through the larva, 

 pupa, and imago states of insect 

 existence. 



METACARPUS. fr. gr. meta, after; 

 karpos, the wrist. That part of 

 the hand which is between the 

 wrist and fingers. 



METAL'LIC OXIDE. A union of a me- 

 tal with oxygen. 



METALLi'FERous.-Containing metal. 



METALLO'GRAPHY. That branch of 

 science which treats of metals. 



METALLOID. Literally, resembling 

 metal. The metals obtained from 

 the alkalis and earths are called 

 metalloids. 



METALLURGY. fr. gr. metallon, a 

 metal ; ergon, work. The separa- 

 tion of metals from the ores, com- 

 prising the operations of assaying, 

 refining, smelting, &c. 



METAMOR'PHIC. fr. gr. meta, indi- 

 cating change ; morphe, form. Me- 

 tamorphic rocks are those which, 

 owing to the presumed action of 

 heat, have undergone change of 

 structure. Altered rocks ; includ- 

 ing gneiss, mica-schist, clay-slate, &c. 



METAMO'RPHISM. fr. gr. meta, indi- 

 cating change ; morphe, form. In 

 geology, mineralogy, &c., the doc- 

 trine of metamorphosis, (p. 177, 

 Book viii). 



METAMOR'PUOSES. Lat. plur. of me- 

 tamorphosis. 



METAMOR'PUOSIS. fr. gr. meta, in- 

 dicating change; morphe, form. 

 Transformation. The change 

 which insects undergo. 



METATA'RSCS. fr. gr. meta, after; ; 

 tarsos, the instep. That part of 

 the foot which is between the in- 

 step and toes. 



MKTATHo'RAX.-fr.gr. meta, between ; 

 thorax, chest. The third ring of 

 the thorax of insects, so called, 

 because it is between the chest 

 and abdomen. 



METKO'HIC a-roxiis.-jlerolites. Stones 



9 



or mineral masses which have 

 fallen through the air, accompa- 

 nied by the disengagement of 

 light and a noise like thunder. 



METEOUO'LOGT. fr. gr. meteoros, float- 

 ing in the air ; logos, a description. 

 The investigation of all the phy- 

 sical causes which affect the at- 

 mospheric condition of our globe. 



MIA'SMA. ) fr. gr. miaino, I conta- 



MIA'SMATA. minate. Applied to 

 any emanation from animal or 

 vegetable substances, or from the 

 earth, which may prejudicially 

 influence the health of those per- 

 sons who may be exposed to it. 



MI'CA. fr. lat. mico, I shine. A mi- 

 neral generally found in thin elas- 

 tic lamina?, soft, smooth and of 

 various colours and degrees of 

 transparency. It is one of the 

 constituents of granite. 



MICA'CEOUS. Of the nature of mica. 

 Glittering; shining. 



MICA-SCHIST. Ger. fr. gr. schistos. 

 slaty, easily split. Mica-slate. A 

 lamellar rock composed of quartz, 

 ordinarily grayish, and a great 

 quantity of brilliant lamellae of 

 mica arranged in scales, or ex- 

 tended leaves. 



MICRO'PYLE. fr. gr. mikros, small ; 

 pule, a gate. The foramen of the 

 ripe seed, comprising the exostome 

 and the endostome of the ovule, 

 which lead to the internal portion 

 of the ovule, or the nucleus. 



MI'CROSCOPE. fr.gr. mikros, little; 

 skopeo. I view. An optical instru- 

 ment which enables us to exa- 

 mine objects too small to be seen 

 by the unassisted eye. 



MICROSCO'PIC. fr. gr. mikros, little; 

 skopeo, I view. Diminutive. Not 

 easily seen without the aid of a 

 magnifying-glass. 



MIDDLE EPOCH. A geological epoch 

 characterized by the presence of 

 the new red sandstone. 



MID'RIB. Costa. The principal 

 vein, or continuation of the peti- 

 ole and the axis of the leaf; from 



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