MKTAPOCEROS. 



MICA-SCHIST. 



or il>ls. wp*li to ordinary lrave, irregulur itnioture to regular, and 

 the like. 2. Foliaceous Metamorphosis (Vireaoentia), when all the 

 parU of a flower auume more or lea completely the Ute of leaven. 



3. Duunion (Dujunctio), when the part* that usually cohere are 

 separated, as the carpel* of a syncarpous piatillum, the filaments of 

 monadelphous stamens, the petals of a monopetaloua corolla, Ac. 



4. Iiii-location (Apostasii) : in this case the whorls of the flower are 

 broken up by the extension of the axis. 5. Viviparousness (Dia- 

 phyais), when the axi> is tiot only elongated, but continues to grow 

 anil form new parts, as in those instances where one flower grows from 

 within another. And, finally, 6, Proliferousness (Ecblastasis),when buds 

 are developed in the axils of the floral organs, so as to convert a simple 

 flower into a mass of inflorescence. A very considerable number of 

 instances an adduced in illustration of these divisions, and the work 

 will be found highly useful as a collection of curious or important facts, 



(Outhe, Dit Mttamorjihose tier Pjtanzen ; Miquel, Commmtatio <U 

 Organorum in t'tgetabihbiu Or/a et Metamorphori ; Roper, De Organi* 

 Planlamm; Lindley, Introduction to Botany; Balfour, Clou-Book of 

 Botany ; Schleiden, Principle* of Scientific Botany, translated by Dr. 

 Lankester.) 



METAPOCEROa [IcnAXiDJK.] 



METEORIC IRON. [!BON.] ' 



METEORIC STONES. fAEBOLlTSS.] 



METEORS. [AEROLITES.] 



METOTIA. iPiFRiDJE.] 



METO'PTOMA, a genus of Fossil MMutca, from the Mountain 

 Limestone of the north of England. 



METRIORHYNCHUS, Dr. Hermann von Meyer's name for a genus 

 of Fossil Crocodilida, found, according to him, in the Lias, the Oxford 

 Clay, at Honfleur, and in the Kimmeridge Clay at Havre. 



M ETROSIDE'KOS (from nvrpa, the heart of a tree, and ffi'Jijpor, 

 iron), a genus of Plants belonging to the natural order Myrtacea. It 

 is distinguished from allied genera by the tube of the calyx not being 

 angular, adhering to the ovarium, the limb 6-cleft ; the stamens 20-30, 

 free, very long, and exserted ; the style filiform, and stigma simple ; 

 the capsule 2- or 3-celled, the cells many-seeded ; the seeds wingless. 

 The species are trees or shrubs, with opposite or alternate leaves, with 

 the flowers pedicellate, not adnate to the branches, as they are in the 

 genera Melaleuca and Callutemon. The last genus, with Angophora, 

 has been recently separated from Metrotidcrot. 



Jt. rera, true Iron- Wood, has opposite ovate-lanceolate acuminated 

 quite glabrous leaves, seated on short petioles; the cymes axillary, 

 pedunculate, many-flowered. It is a native of Java and Amboyna, 

 among rocks. The Chinese and Japanese value the wood of this tree, 

 which they apply to many purposes, as the making of rudders, anchors, 

 4c., for their ships and boats. The bark is used in Japan as a remedy 

 in mucous discharges, diarrhoea, and dysentery. It is usually mixed 

 with some aromatic, as penaug, cloves, or nutmeg. 



M. pulymorpha has opposite coriaceous leaves, of various forms, 

 glabrous on both surfaces, but covered with a little silky tomentuui 

 beneath ; the peduncles 3- or many-flowered, terminal and axillary, 

 corymbose; the calyxes and branchlets glabrous or clothed with silky 

 tomentum. This species is a tree, and grows in the Sandwich Islands, 

 and is said to be the plant from which are made the clubs and other 

 weapons employed in warfare by the South Sea Islanders. " The 

 Aki, or Lignum Vit;o of New Zealand, the Rata and the Pohutu 

 Kawa of the same country, are all hard-wooded trees belonging to the 

 genus Mctrotiderot." (Lindley.) 



Several other species of Metrotiderot have been described, natives 

 of Australia and the South Sea Islands. M. lucida, a beautiful 

 tree, occurs as far south as Lord Auckland's Islands, in lat. 504 S. 

 The M. lu.rifolia of Allan Cunningham is the New Zealand plant 

 called Aki, and is a rambling shrub, adhering to trees, and climbing 

 by means of its lateral roots to the summits of the loftiest trees in 

 the forests of Wangaroa and the Bay of Islands. In cultivation these 

 plants may be grown in a mixture of loam, peat, and sand. They 

 may be propagated by seeds or cuttings. Ripe cuttings will root in 

 Mod under a Land-glass. 



(Don, IKclilamydimu Planli; Lindley, Vegetable Kingdom ; Burnett, 

 Outline* of Botany.) 



MKL'M (from fuittr, smaller), a genus of Plants belonging to the 

 natural order UmoeUiferce and to the tribe Seiclinae. It has an 

 obsolete calyx ; entire elliptical petals, acute at both ends, with on 

 incurved point; the fruit elliptical, terete, or slightly doraally 

 compressed ; the carpels with 6 sharp somewhat winged ridges ; the 

 intention aixl commissure's with many vitto). There are two niiccies 

 of this genus. 



if. Alkamantictm, Common Bald-Money, has bipinnuto leaves with 

 multipartite leaflet*, the segments thread-shaped, acute. This is a 

 highly aromatic plant, with numerous white and yellow flowers. It 

 is a native of Europe, in dry mountain pastures, and is found in 

 England and the mountains of Scotland. The roots, seeds, and every 

 part of the plant are aromatic, and are used in the countries where it 

 grows as stomachics and carminatives. This and the other species, 

 M.M*ttllina, the Swiss Bald Money, which is a native of the sub- 

 alpine pnrtures of Europe, enters into the coin position of the compound 

 called Venice Treacle. 



( Babington, Manual of SriliA Botany ; Lindloy, Vegetable Ki vgdom.) 



MEW. CLARID.B.1 



MEZEREON. [DAPHNE.] 



MICA, a Mineral belonging to the extensive aeries of Silicates of 

 Alumina. It occurs in oblique rhombic prisms of about 120* and 00'. 

 The crystals usually with the acute edge replaced. The cleavage is 

 very decided, yielding easily thin elastic lamina) of extreme tenuity. 

 It is found usually in thinly foliated masses, plates, or scales : some- 

 times in radiated groups of aggregated scales or small folia. The 

 colour is from white, through green, yellowish, and brownish shades, 

 to black. The lustre is more or less pearly. Transparent or trans- 

 lucent. Tough and elastic. Hardness 2'0 to 2'5. Specific gravity 

 2-8 to 8-0. 



The composition of mica is as follows : 



Silica 46-8 



Alumina 36-8 



Potash 9-2 



Peroxide of Iron . . . . . . 4*5 



Fluoric Acid 07 



Water 1-8 



99-3 



A variety in which the scales are arranged in a plumose form is 

 called Plumose Mica ; another in which the plates have a transverse 

 cleavage, has been termed Prismatic Mica. 



Mica resembles externally talc, and some forms of gypsum. From 

 talc it differs in affording thinner lamina;, and being elastic. It also 

 has not the greasy feel of talc. The same characters except the last 

 distinguish it from gypsum, besides it does not crumble so readily on 

 heating. 



Mica is one of the constituents of granite, gneiss, and mica-slate, 

 and gives to the latter its laminated structure. It also occurs in 

 granular limestone. It is found abundantly in the United States, in 

 Russia, in Great Britain, and other parts of the world. It is not often 

 found in large isolated masses, but filling up the veins and fissures of 

 rocks, into the composition of which it enters. It occurs in the oldest 

 rocks, as well as in those which are new and possess a crystalline 

 character. 



In Russia it is used extensively as a substitute for glass, and hence 

 it is called Muscovy Glass. The very thin lamina) are employed 

 for examining objects under the microscope. Haiiy states that these 

 lamina: are sometimes not more than the l-300,000th part of an inch 

 in thickness. 



Lepidolile, or Lithia Mica, occurs in crystals or lamina) of a purplish 

 colour, and often in masses consisting of aggregated scales. It occurs 

 in the Ural. According to Resales, as quoted by Dana, it consists of 

 the following analysis : 



Silica 477 



Alumina . 



Lime .... 



Protoxide of Manganese 



Potash .... 



Lithia 



Soda . . . . 



Fluorine . 



Chlorine 



20-3 

 6-1 

 47 



11-0 

 2-8 

 2-2 



10-2 

 1-2 



-1062 



Fuelaitc is a green Mica from the Zillerthal, containing nearly 

 4 per cent of oxide of chromium. 



From the crystallisation of Mica two species have been mode out 

 of the old species so called. The common Mica has an oblique prism 

 for its primary, but many micas when in perfect crystals have the 

 form of a hexagonal prism. This species has been called hexagonal 

 mica, the dark -coloured micas of Siberia, and the brilliant hexagonal 

 crystals of Vesuvius. There are also hexagonal crystals which have 

 been found by L)ov<5 to have two axes of polarisation, indicating that 

 the lateral axes of the primary are unequal, and that the form is a 

 rhombic prism with the acute edges truncated. This species is called 

 Rltomvic Mica, or Phlogo]ihite. 



Maryarite, or Pearl Mica, occurs in hexagonal prisms, having the 

 structure of mica, and also in intersecting lamina). It has the appear- 

 ance of talc, but diners from that mineral in being a silicate of alumina 

 instead of magnesia. It is found at Stcrziug in the Tyrol, associated 

 with chlorite. 



Maiyarotlite, another schistose talc of Zillcrthal, ii a variety of 

 common mica. 



i'merylite and Eupliyllile ore new species, somewhat related to 

 Maryarite. They are found in Pennsylvania, United States. 



Kamte. resembles talc, but contains no magnesia. It is whitish and 

 soft, and has a greasy feet 



Lcjiidomtlane is a black iron mica, occurring in 6-sided scales or 

 tables aggregated together. 



Ottrelite is an allied mineral occurring in black scales. 



Oderit is probably a black mica. It can bo split into thin leaves. 

 It is opaque, black, and has very little lustre. It occurs in Sweden. 



.MICA-SCHIST, one of the earliest groups of Stratified Rocks 

 known to geologists, and very extensively distributed throughout the 

 mountain regions of the globe, often in contact with granite, but more 

 requeutly superposed on gneiss. It is frequently interatratified with 



