811 



FLOWERING-FERN. 



FLYING. 



Si2 



also the variety and splendour of the colour. The following are the 

 iiKiin points in the structure of this organ : 



The individual petal exhibits, on a reduced scale and in a delicate 

 condition, almost every variety of form of the leaf, with the 

 exception of the truly compound. CoAcave forms are here frequent, 

 such as the hood-shaped, pitcher-shaped, or spurred petals, &c. ; 

 these latter very often on individual petals of an otherwise regular 

 corolla as in Fumaria. Fringed and feathered forms, aa well as 

 variously lobed petals, are also by no means rare. The limb and 

 the claw are often clearly to be distinguished. Parts analogous 

 to the ligule, and every imaginable form of appendage, with the 

 exception only of the stipules, occur frequently, and characterise 

 genera and families. 



On this account it is indispensable to distinguish the simple 

 appendages of the petals from the independent foliar organs. To 

 the former belong the scales (fornices) of the JSorayinacece, the 

 scales of the corona of the Silenacece, the formations generally 

 described as coronas in the Stapeliaceie and some other Asclepiadacece, 

 the nectaria of Ranunculus, Panuuna, &c. 



The corolla consists of one circle, rarely of two (three series in 

 Berberit), or more (four series in Nympluxa). In Monocotyledons the 

 number of members is equal to those of the calyx ; in Dicotyledons 

 the number of five in a circle predominates, though it is some- 

 times composed of two, of four, or of a greater number in Dryas. 

 The number of members is equal to that of the calyx, or greater ; 

 very rarely indeed it is smaller ; this last case occurs with Hibiscus. 

 Suppression is not infrequent, and sometimes involves all the foliar 

 organs of a corolla at once, as in the summer flowers of many 

 species of Viola, in Lejiidium ritderale, and in some species of Acer. 

 The coherence of organs in every way is still more frequent; never 

 indeed with the calyx or the germens, but frequently with the 

 stamens. 



The corolla, whether with free or with coherent petals, may be 

 regular or only symmetrical. In the latter the bilabiate formation 

 is the most frequent, especially in five-membered circles, hi such a 

 way that, according as the odd petal is on the upper or the under 

 side of the flower, the upper lip consists of three or of two petals. 

 In the hitter case these two are very often little or not at all 

 coherent, as in Teucrium, the so-called radiated flowers of the 

 Compotila (floribus ligulatis vel radiatis). Peculiar forms of sym- 

 metrical flowers are, for instance the personate flowers (corolla 

 pcrsonata), in which the upper petals of a coherent corolla are so 

 curved inward that they close the entrance of the tube (as in 

 Antirrhinum), the incurved portion is termed the palate (palatum) ; 

 the true bilabiate or mouth-like corolla (corolla ringens), in the 

 Lalnatte, in which the two petals forming the upper lip often present 

 a concave form overhanging the lower lip, termed galea ; the so-called 

 papilionaceous flowers of the Leguminoce, in which the uppermost 

 leaf, which is broad and large, surpassing the others, is termed the 

 standard (vexillum), whilst the lateral petals, as wings (alac), are 

 usually dissimilarly developed, and the two undermost, very frequently 

 coherent, also developed unequally at the two sides, approach each 

 other in a concave form, so as to form the keel (carina). Sometimes 

 all the petals of the papilionaceous flowers become coherent at the 

 lower part, and form a tube, as in Trifolium ; or individual petals 

 are abortive, &c. The most irregular of all the forms have hitherto 

 received no names ; such as appear for instance in the Polygalawi?, 

 the Baltaminacece, Tropaolafeie, 4c. 



All that was said respecting the structure of the perianth holds 

 also for the structure of the corolla, remembering only that this is 

 more delicate. The contents of the cells vary much in colouring 

 matter, and their distribution in groups is sometimes very remark- 

 able. Very dense texture, in consequence of the presence of much- 

 thickened porous cells, as in the Amarantacece, is infrequent. The 

 structure of the epidermis, and its development into papilla;, hairs, 

 &c. is very manifold. Development into surfaces secreting nectar, 

 both at the bottom of concave forms and upon the appendages, is 

 especially common. The petals also occasionally secrete a viscous 

 substance, in consequence of which they adhere together, as happens 

 at the points of the inner petals of the Pumariacect. 



The Epicalyx is seen where three separate series of foliar organs 

 are distinguishable in the floral envelopes, and it is the outermost of 

 these. There are not many plants which exhibit an epicalyx. In 

 form and structure it much resembles the calyx. It occurs with 

 free leaves (as in Ptutijtora), and coherent leaves (as in Lavatera). Its 

 leaves are seldom delicate, such as are seen in the corolla, but are 

 often dry and membranous (as in Kcabioia), but generally green and 

 leafy (as in the Malracnr). 



For an account of the other organs of the flower, see STAMEN ; 

 FRCIT; PISTIL; SEKD. For the functions of the flower, see REPRO- 

 DUCTION IN PLANTS. 



(SrMeiden, Principles of Scientific Botany.) 



I I.OWKKIN'i; KKItX. [08MUNDA.] 



FLOWERING-RUSH. [BUTOMACE*.] 



FMJCKKINE, the name given to the native Deutofluate of Cerium, 

 which occurs at Finbo and Broddbo, near Fahlun, in Sweden. It 

 occurs both massive and crystallised. The crystals are either six- 

 sided plates or prisms; they have a yellow or reddish colour; 



fracture uueven ; dull ; translucent, in very thin fragments : when 

 heated by the blow-pipe on charcoal it becomes slightly brown, but 

 does not fuse ; in the reducing flame it becomes colourless, and in 

 the oxidating flame, with borax and a phosphate, it yields an orange- 

 coloured globule : when heated in a tube with an acid, the glass is 

 corroded. 



FLUELLITE, a compound of Fluoric Acid and Alumina, which 

 occurs at Stenna-Gwyn, in Cornwall, iu octahedral crystals, the 

 primary form being a rhombic prism : the crystals are colourless and 

 transparent, with a vitreous lustre. It is extremely rare. 



FLUKE. [PLEURONECTID.E.] 



FLUKE-WORM. [ENTOZOA.] 



FLUOR. [FLUOR-SPAR.] 



FLUOR-SPAR, Fluor, Fluate of Lime, Derbyshire Spar, is a well- 

 known mineral, which occurs in many parts of the earth, but 

 especially and in great plenty in Cornwall, Derbyshire, and Durham. 

 It occurs both crystallised and massive. The primary form of the 

 crystal is a cube, the cleavage is parallel to the planes of the regular 

 octahedron, distinct, but seldom with perfect surfaces : it assumes a 

 vast number of secondary forms, as the octahedron, rhombic 

 dodecahedron. The late W. Phillips mentions his possessing at least 

 70 beautiful varieties of form, and he has figured a fragment of a 

 crystal from Devonshire which, if it were perfect, would exhibit 

 322 planes. It occurs colourless, and of almost every colour, as 

 gray, purple, black, brown, red, yellow, green, and blue : in Derby- 

 shire the last is the prevailing tint, and the massive Fluor of that 

 county is termed by the miners ' Blue John.' It is frequently 

 transparent, but more commonly only translucent; its lustre is 

 vitreous. Specific gravity 3'1 4. Hardness 4 '0. Streak white, or slightly 

 coloured. Fracture conchoidal. When powdered and thrown on a hot 

 coal, Fluor-Spar exhibits a phosphorescent light, which is blue, green, 

 purple, or yellow ; when thrown in mass into the fire, it decrepitates. 

 The massive varieties are nodular or amorphous : the structure of 

 the former is large fibrous, or columnar, with divergent fibres : the 

 structure of the amorphous variety is crystalline, granular, earthy, 

 compact, and occasionally straight or curved laminar. The crystallised 

 varieties are more common in Cornwall and the west of England ; 

 the massive varieties in Derbyshire and the north of England. It 

 occurs in many places on the Continent also. In the United States 

 of America a variety called CMorophane is found at Huutingtoii, 

 Connecticut. 



Fluoride of Calcium is found in the teeth, in bones, and iu the 

 ashes of plants. It is used for obtaining Fluoric Acid, which is 

 employed in etching. [FLUORIC ACID, in ARTS AND So. Div.] 



Fluor-Spar is, strictly speaking, to be considered as a Fluoride of 

 Calcium, composed of 



One Equivalent of Fluorine 

 One Equivalent of Calcium 



18 

 20 



Equivalent . . .38 



The blue and variegated Fluor-Spar of Derbyshire is turned into 

 various ornamental forms, candlesticks, &c. ; that of Cornwall is 

 used as a flux in the reduction of copper-ore. 



FLUSTRA. [CELLARI.EA.] 



FLY, a name applied almost indiscriminately to all insects 

 possessing wings ; by many however restricted to the various species 

 of Dipterous Insects, an account of which is given under the head 

 DIPTERA. 



FLY-TRAP, VENUS'S. [DION^A.] 



FLYING consists in the power which many animals possess of 

 raising themselves in the air, and in moving through it in various 

 directions, supported by the atmosphere alone. 



In the article SWIMMING it is shown that man and many of the 

 lower animals are very nearly equal in weight to an equal bulk of 

 river water; consequently a man's weight is very nearly or quite 

 supported when he is immersed in water. But the case is widely 

 different when he is in the air, as the density of this is to that of 

 water very nearly as If to 1000 ; hence it follows that a man should 



]| 

 be JQQQ less in weight than he is at present, in order thai he might 



be supported in the air with as little effort as he is in water. The 

 physical constitution of the air is also very different from that of 

 water, and presents other obstacles to the efforts of a man to raise 

 himself in that medium. 



The air is compressible, and consequently much heavier near the 

 surface of the earth than it is in the elevated regions of the atmo- 

 sphere ; and it appears from numerous experiments that as the height 

 increases in an arithmetical, the density decreases in a geometrical 

 progression. Thus, supposing an animal to ascend in the air 34, 7, 

 14 miles, the density at the surface, being unity, would decrease in 

 the ratio of the numbers J, i, j' a ; so that if the animal were as light 

 as the air itself at -the surface of the earth it would continually 

 increase in weight with respect to it as it ascended, and could not be 

 supported unless a force equal to the difference between the weight 

 of the animal and its own bulk of air were properly applied for that 

 purpose. 



It appears from an elaborate investigation of M. Chabrier that the 



