617 



ROEBUCK. 



ROOT. 



613 



the fore arms have scarcely auy rotatory motion, and their two bones 

 are nearly united ; in a word, the inferiority of these animals shows 

 itself in the greater part of the details of their organisation. Never- 

 theless, the genera which have the strongest clavicles enjoy a certain 

 dexterity, and use their fore feet for carrying their food to their 

 mouth; others again (the Squirrels) climb trees with facility. ('Regne 

 Animal') 



Preparations of the structure of these animals may be seen in the 

 museum of the Royal College of Surgeons. 



The following animals are arranged by Cuvier under the order 

 Rodentia : 



The Squirrels (Sciurvi, Linn.), namely, the Squirrels properly so 

 called (Sctitriw, CUT.) ; the Flying Squirrels (Pteromye) ; and the Aye- 

 Aye (Cheiramyi). 



The Rats (ifut, Linn.), namely, the Marmots (Arctomys, Spermo- 

 philun); the Dormice (Myoxus, Qm.); the Spiny Rats (Echimys, 

 Hydromyt, Capromys) ; the Rats properly so called (3{u, Cuv.) ; the 

 Jerbilles (GerbiUtu, Meriona) ; the Hamsters (Cricetus) ; the Field- 

 Rate (Arvicola, Lacep.), subdivided into the Ondatras (Fiber, Cuv.), 

 the ordinary Field-Rats (Arvicola, Cuv., Ifypudteus, 111.), and the Lem- 

 mings (Georychui, III) ; Otomys, and the Jerboas (Dipus, Gm.). 



The Jumping Hares (Hdamyt, F. Cuv. ; Pedeles, 111.). 



The RatrMoles (Spalax, Quid.). 



Bathyergus (Orycteres, F. Cuv.). 



Gemnyt (Pseudontoma, Say; Aicomys, Licht.). 



Diploitoma, Raf. 



The Beavers (Cottar). 



The Couias (Myopotamus, Com.). 



The Porcupines (Hyatrix, Linn.), namely, the Porcupines properly 

 so called (Ifystrix, Cuv.) ; Atherurut, Cuv. ; Erelhizon, F. Cuv.; and 

 the Coendous (Synetkerei, F. Cuv., Ccrcolobes, Brandt). 



The Hares (Leput, Linn.), namely, the True Hares (Leput, Cuv.), 

 and Lagomyi, Cuv. 



The Capybara (Ilydroch&riu, Erxl.). 



The Guinea-Pigs (Ancema, F. Cuv. ; Cavia, III). 



The Mocos (Kerodon, F. Cuv.). 



The Agoutis (Chloromye, F. Cuv. ; Datyprocla, 111.) ; and 



The Pacas (Ccelogenyt, F. Cuv.). 



In this work the genera and species of Rodenlia have been des- 

 cribed under the following heads : CHINCHILLID.E, HYSTHICID.E, 

 LEPORINE, MURID.E, SCUIBID.E, BEAVEU, ONDATRA, CCELOGENTS, 

 AGOUTI, and KERODON. 



ROEBUCK. [CERVID.K.] 



ROEMERIA (named after Dr. John James Romer, professor of 

 botany at Landshut ; he was author of several botanical works, and 

 died in 1820), a geuus of Plants belonging to the natural order 

 Papateracca. It baa 4 petals, numerous stamens, 2-4 sessile stigmas, 

 an elougated 2-4 valved 1 -celled capsule with distinct placentas. The 

 species are annual herbs yielding a yellow juice, with violet flowers. 



R. hybrida, Hybrid-Roemeria, has a 3 valved erect pod with a few 

 rigid leaves at its extremity. This plant is a native of Europe and 

 the north of Africa, in cultivated fields and vineyards, especially on 

 the coasts of the Mediterranean. It is also found in England in 

 chalky corn-fields in Cambridgeshire and Norfolk. Although now 

 having the appearance of a native, this plant has been probably 

 introduced into this country. Two other species, R. refracta and R. 

 bivalvit, have been described : the first a native of Tauria, the second 

 of Syria. 



(Don, Dichlamydeoua Plants ; Babington, Manual of British 

 Botany.) 



HOLLER. [CoRACiAS.] 



ROMANZOVITE. [GARNET.] 



ROMEINE, a Mineral occuriug crystalised in square octohedrons, 

 in groups of minute crystals. Colour hyacinth, or honey-yellow. 

 Hardness, scratches glass. It is found at St. Marcel, in Piedmont. 



Its analysis by Damour gives : 



Antimonious Acid 79'17 



Lime 16'65 



Protoxide of Manganese 2'16 



Protoxide of Iron 1'19 



Silica 0-60 



99-77 



RONDELE'TIA, a genus of Plants belonging to the natural order 

 Rubiacvt, named after Rondelet, a French botanist of the 16th 

 century. It is characterised by having a calyx with a subglobular 

 tube. Corolla superior, funnel-shaped, ventricose at the throat; seg- 

 ments 4-5, ovate-obtuse, spreading; anthers 4-5, sessile within the 

 corolla; ovary 2-celled ; style filiform ; stigma bifid ; capsule round, 

 crowned with the limb of the calyx. Seeds minute, numerous, or 

 few when abortive. The genus, as formerly constituted, included 

 many shrubby trees which occur in India (Roxb., ' Fl. Indica '), but 

 thene have been referred by modern botanists to Adenotacme, Qreenia, 

 and Wendlandia. The present genus llondelctla occurs chiefly in 

 America and the West Indies. 



ROOK. [CORVID*.] 



ROOT is that part of a plant which is sent downwards into the 

 earth, at the same time that the stem is sent upwards into the air. 

 Every part of the plant which exists underground is not root, as 



large portions of the stem itself may remain under the surface of 

 the earth ; and large buds, called bulbs, also exist underground. These 

 parts have been often confounded with the root. The creeping root, 

 and some forms of the tuberous and bulbous roots of older botanical 

 writers, are only so many different forms of the stem. [ExoGENS.] 



The root is distinguished by certain structural peculiarities, by 

 which it may be easily know from the stem. First, its ramifications 

 are irregular, not having the symmetrical form of branches, nor are 

 they developed like branches from buds. Secondly, roots generally 

 produce no leaf-budi;. When they do appear, which occasionally 

 occurs, they are called adventitious buds. Thirdly, roots never have 

 leaves, scales, or other appendages developed upon their surface ; and 

 fourthly, the cuticle of roots is never found to possess stomates, 

 which are frequently very numerous on various parts of the stem. 



The smaller divisions of roots are called fibrils, which consist of a 

 little bundle of ducts or spiral vessels, surrounded by woody fibres, 

 lying in a mass of cellular tissue. At the apex of the fibril the 

 cellular tissue is loose and devoid of cuticle, from which cause it 

 absorbs more rapidly the fluid by which it is surrounded than the 

 other parts of the root. Although the terminations of the roots 

 cannot be considered as special organs, they have been named by De 

 Candolle spongelets, or spongioles, in reference to their absorbing 

 power. 



The relation between the size and extent of the roots and that of 

 the branches varies very much. In some tribes, as the Conifene and 

 Palmacece, the roots are very insignificant compared with the size of 

 the stem. In other plants the roots are much the longest, as in the 

 lucern, &c. In the greater proportion of trees the roots extend wider 

 than the branches, but do not penetrate so deep as the stem is high. 



The internal structure of the root resembles that of the stem, but 

 in Exogens the roots do not possess a central pith. The cellular 

 tissue of many roots is exceedingly abundant, and on this account 

 they are used as articles of diet. Many of these roots, by attention 

 to their culture, may be increased in size ; and the growth of esculent 

 roots is an object of importance in the kitchen-garden. The principal 

 esculent roots are : the Jerusalem Artichoke (Helianthus tuberosus) ; 

 Turnip (Bratsica Rapa) ; Carrot (Daucus Carota); Parsnip (Pastinaca 

 saliva) ; Red-Beet (Beta, vulgaris) Skirret (Slum, Sisarum) ; Scorzo- 

 nera, or Viper's-Grass (Scorzonera ffispanica); Salsafy, or Purple 

 Goafs-Beard (Tragopogon porripolius) ; Radish (Raphanus sativua). 

 Besides these, which are commonly cultivated, there are many of our 

 native plants which possess roots yielding a nutritive matter, and are 

 occasionally used as articles of diet. The Arrow-Head, Common 

 Arum, Bitter Vetch, or Mouse- Peas, Earth-Nut, Meadow- Sweet, Pile- 

 wort, Silver-Weed, Solomon's Seal, and Common Comfrey, are 

 recorded as yielding edible roots. (' Cyclopaedia of Gardening.') 



During dry seasons and in dry situations the roots of many plants 

 swell and become tuberous, which seems to be a provision for supplying 

 nutriment to the stem and its appendages. 



Roots are called annual, biennial, or perennial, according to their 

 duration. When a root perishes after its first year's herbage and 

 flowering, it is annual ; if after the second year's herbage and first 

 year of flowering, it is biennial. If a root endures for many years, 

 although its herbage may perish every year, it is perennial. 



There are various forms of roots distinguished by botanists. The 

 Fibrous Root possesses a multitude of small divisions of the fibr'Usa, 

 as is seen in the Poa annua and many other grasses. The Noduloso 

 Root presents occasional dilatations, as in the Phleum nodoswm. A 

 Prsemorse Root is one in which the extremity of the primary axis has 

 perished, or its development has been prevented by the extension of 

 librilUe from its sides, as in the Devil's-Bit Scabious (Scabiosa succisa). 

 The Fusiform Root is seen in the carrot and turnip ; such plants are also 

 called Tap-Rooted. The term Tubercules is applied by some to the 

 roots of the Orchis and Dahlia ; the former are palmated, or lobed, 

 the latter are fasciculated. 



Although most if not all the higher plants possess roots, amongst 

 many of the lowest forms they are not to be distinguished. The 

 lower plants which float about in water, as the OsciUatoria, Dialoma, 

 &c., and which consist of little more than simple cells, possess no 

 appendages which can be called roots. In many of the Conferva a 

 downward development of the cells of cellular tissue, attaching them 

 to the objects on which they grow, has been observed. Some of the 

 Lichens, as the L. esculentus of Pallas, and the lower forms of Fungi, 

 as the Tremellas, &c., possess no roots. Many of the floating water- 

 plants, as the Aldrovanda vaiculosa, do not develop roots, and derive 

 their nourishment from the medium in which they live by the direct 

 contact of the cellular tissue. In fact we find that the simple cells 

 of cellular tissue in the lower plants perform all those functions 

 which, as we ascend in the scale of organisation, . are performed by 

 particular parts of the plant. In the Charas and the Marchantia, the 

 roots become more evidently developed, and the downward growth 

 of the cells is more observable than in the Conferva. On the lower 

 surface of the Marchantia, prolongations of the cellular tissue are 

 observed, which Meyen calls root hairs or capillary fibrils. In the 

 Equwetacea and Ferns the roots become more perfectly developed, 

 and their surface is almost entirely covered with capillary fibrils. 

 These fibrils are developed on almost all roots, and perform the 

 function of absorption. 



