1185 



VARIOLARIA. 



VEGETABLE KINGDOM. 



1186 



points of structure which are developed only under certain circum- 

 stances, and which are not essential to the species. This may be illus- 

 trated by an example as, for instance, the common apple (Pyrui 

 malua). If the seeds of the wild apple, or any of the cultivted varieties 

 of apples, are sown under any circumstances, the plants that spring 

 from these seeds will, in the great mass of their characters, be more 

 like all other apple-trees than they will be like pear, plum, or any 

 other trees. This then illustrates the idea of a species. If, on the 

 other band, the seeds of some of the sorts of apples, known under the 

 names of Qolden Pippin, Nonpareil, &c., be sown under different cir- 

 cumstances from that in which the plant from which they are taken 

 was grown, the plants produced will differ in many respects from their 

 parent iu the characters that constitute the variety, but not in those 

 of the species. The characters on which the definition of a species is 

 founded ought to be such that no circumstances can alter them, whilst 

 the essence of a variety consists iu its having characters which are 

 altered and produced by circumstances. Buds propagate the character 

 of the variety, but seeds continue the species. 



The natural varieties of plants are nothing like so numerous as those 

 which arise from cultivation- Almost the entire object in view iu the 

 kitchen- and fruit-gardens is the developing of some property in plants 

 which they do not exhibit in their natural state, and this is mostly 

 attended with a corresponding change of structure. All the varieties 

 of apples are produced by cultivation from the common crab (Pynts 

 iiiilui) ; all the pea-s from Pyrus communis ; the cherries from Primus 

 Ceratus; peaches, apricots, nectarine?, from Amygdalus Periica; and 

 plums from the Prunia domeitica. The same is true of vegetables : 

 all the varieties of cabbages are produced by cultivation from the same 

 species ; so also with turnips, potatoes, radishes, &c. This is also the 

 case with flowers : the great majority of tulips, roses, anemones, 

 Ranunculi, &c., found in gardens, are the result of changed characters 

 dependent on cultivation. Although many of the varieties of fruits, 

 vegetables, and flowers, retain the same names for a great length of 

 time, there is nothing permanent iu their character? but those which 

 belong to the species. 



VARIOLA'RIA, a genus of Plants belonging to the natural order 

 of Lichencs. This name is derived from ' variola!,' because the apo- 

 thecia resemble the pustules of small-pox. The thallus of the plants 

 belonging to this genus is crustaceous, membranaceous, adnate, 

 spreading, uniform. The apotbecium is a suborbicular scutelliform 

 cup, formed of the thallus, and filled with a powdery or flocculose 

 substance which covers an immersed waxy disc containing imbedded 

 tbecas. The species are of an ash-gray or white colour, and are found 

 on the back of the trunks of various trees, on rocks, walls, or on the 

 ground. About 13 species are found in Great Britain. 



V.faginea, the Bitter-zoned Variolaria, has an orbicular crust, sur- 

 rounded by a zonate border of various colours ; the apothecia are very 

 abundant, convex, with an obsolete border, and filled with a suowy 

 white powder. This is one of the species included in the Lichen 

 faginem of Linnanis. It is common on the bark of trees, especially 

 of old beech-trees, and on pales. This species is distinguished from 

 all others of the genus, as well as of the order, by its intensely bitter 

 taste. It is for this reason that Turner and Borrer have separated 

 the V. diicoida from this species, although it has only a very slight 

 structural dissimilarity ; but it has no bitter taste at all. Braconnot 

 found that the V. faginea, as well as several other crustaceous lichens, 

 contained oxalic acid. The quantity yielded by 100 parts of this 

 plant was 29-4 of oxalic acid, combined with 18 of litne. It is at the 

 present time employed in France, on a very extensive scale, for the 

 purpose of obtaining oxalic acid. 



V. laclea, Milky-White Variolaria, is ono of the lichens that are 

 collected for the purpose of being used in dyeing. 



V. globulifera, Vesicle-Fruited Variolaria, is found only rarely, 

 growing on the bark of old oaks and beech-teees. It was gathered 

 by Dr. Sibthorp in Greece ; and, on account of the form of the 

 reproductive organs, is the most remarkable-looking species of the 

 genus. 



I'. rinlif/n. Leprous Variolaria, has an elliptical, very thin, almost 

 filmy, whitish crust, with very numerous, minute, oblong, confluent 

 apothecia, having a very narrow elevated margin, and containing a 

 1. u! r oloured powder. This is one of the most common species of the 

 genus, and is common on old rails and gate-posts, giving them the 

 appearance of having been imperfectly daubed over with white paint. 



VAKNISK-TRKE. | MELANORRHEA.] 



VARVICITE. [MANGANESE.] 



VASCULAR TISSUES. [TISSUES, VEGETABLE.] 



VASCl/'LARES, iu Botany, applied to the two principal classes of 



plants, Exogen.1 and Endogens, on account of their highly-developed 



ilar tLsuex, in opposition to tbe class of Acrogens, the tissues, of 



:i are principally cellular, and htnce they are called Cellulares. 



INS; KNM;KNS: Aciwr 



VATE'RIA, a genus of .Plants belonging to the natural order Dipte- 



,>acerc. It is characterised by having the calyx 5-cleft; segments 



"gth refl.xed; petals 5, oval, emarginate, twisted in the bud: 



RUmens 40 to 50, short, inserted between the petals and tbe base of 



t.hu germ; anthers long, linear; capsule 3-valved, 1-celled, and 1- 



eedeil ; cotyledon* stalked. 



The species are two in number, V. Indica, which grows all along the 

 KAT. HIST. DIV. VOL. rv. 



Malabar coast and in Canara ; and V. lancecefolia, which is common 

 in Silhet. Both species form large trees with entire smooth coriaceous 

 leaves, and terminal panicles of white flowers ; and both are valuable 

 not only as timber-trees, but for yielding valuable, almost unique 

 products. V. Indica grows to the height of about 60 feet, and yields 

 valuable timber, which is mucli employed in ship-building, and is not 

 liable to be attacked by the teredo. When the bark is wounded, a 

 pellucid, fragrant, acrid, bitter, resinous fluid exudes, which in the 

 rays of the sun becomes yellow and fragile like glass. This resin is 

 well known in commerce, and is usually called Copal in India, but 

 when imported into England receives the name of Gum Anime. The 

 fluid resin also makes a good varnish, which is called Pundum, or 

 Liquid Copal; on the Malabar coast it is often called Piuey Varnish, 

 and the tree Piney Varnish-Tree, or Piuey Marum. The dry resin, 

 boiled with more or less oil, is used for the purposes of tar and resin ; 

 it is also employed by the natives instead of frankincense. Besides 

 these, another very valuable product is yielded by this tree, and that 

 is a fatty substance, which is known by the name of the Piney Tallow, 

 or Vegetable Tallow, of Canara. This is obtained by boiliug the 

 seeds, when the fatty substance floats to the surface, and on cooling 

 down becomes of the consistence of tallow. In colour the different 

 specimens vary from pale yellow, or fawn, to perfect white. Its 

 general properties, such as its hardness, colour, combustibility, and 

 fusibility, place it between wax and tallow ; but it is far superior to 

 the latter, Laving no disagreeable smell, either when burning or at 

 common temperatures. 



V. lancecefolia is the other species, which was described by Dr. 

 Roxburgh from Silhet, where it is called MoaL Like its congener, 

 this also exudes a clear liquid from wounds, &c., in the bark, which 

 soon hardens into an amber-coloured resin. From this the natives 

 distil a dark-coloured and strong-smelling resin called Chooa, and 

 Chova and Gond by the Brahmins, who use it as incense. 



VAUCHE'RIA, a genus of Plants belonging to the inarticulate 

 Algae, named after Professor Vaucher of Geneva. This genus belongs 

 to the tribe Siphonece, and was formed by De Candolle. from Vaucher's 

 genus Ectosperma. The fronds or filaments are aggregated, tubular, 

 continuous, capillary, and coloured by an internal green coloured 

 mass. The fructification consists of dark green homogeneous vesicles, 

 which are attached to the filaments. The species are found in pools 

 and ditches nnd stagnant waters, on damp ground, and on the mud of 

 salt-water rivers and in the sea. 



V. dichotoma, Large Dichotomous Vaucheria, has dichotomous 

 filaments, with solitary globose sessile vesicles. This is one of the 

 most common of the species, and is found, in spring and autumn, iu 

 pools and ditches of fresh water, and Mr. Berkeley has found a variety 

 in the sea. It is one of the largest of this genus, its filaments being 

 often more than a foot long, and filling up the ditches on account of 

 their number. 



V. Dillwynii, Dillwyn's Vaucheria, has branched flexuose filaments, 

 with globose lateral sessile vesicles. This species is common on the 

 ground in damp situations, forming a thin intricate fleece of a green 

 colour. 



V. clavata, Clubbed Vaucheria, has short filaments terminating with 

 a vesicle, which contained the sporules. This species does not appear 

 to be an inhabitant of Great Britain. It inhabits ditches of clear 

 water, and is interesting on account of the observations made upon it 

 by Unger. Whilst examining this plant, he found that the vesicular 

 summits had the power of contraction, aud that by this process they 

 expelled the contained sporules, which after their expulsion ascended 

 to the surface of the water. " As I continued my observation," says 

 Unger, " I happened to look at the surface of the water, and was not 

 a little astonished to find it covered, especially towards the side of the 

 vase, with minute globules, unequal both in colour and size. Many 

 of them swam freely here and there, moving at their option in one 

 way or another, retiring and approaching one another, gliding round 

 globules that were motionless, stopping and again setting themselves 

 in motion, exactly like animated beings. Conjecturing the identity 

 of the green globules that possessed motion with those that had none, 

 I immediately began to examine whence these infusory animalcules 

 derived their origin, aud what relation they bore to the green globule 

 and the fructification of the Conferva. The next day I perceived a 

 great number of globules aggregated arouud the bubbles of gas disen- 

 gaged from the Conferva, and floating at the surface. There were 

 some of them of a dark geeen colour, and either round or elongated ; 

 others more transparent, humid, aud with one or two appendages 

 diverging from or at right angles with each other : these were evi- 

 dently plants in a state of germination. Other globules again were 

 oval, very dark at one extremity, and almost transparent at the other; 

 these swatn about freely. Within the space of one hour I succeeded 

 in tracing not only the diminution of vitality and death of the Infu- 

 soria, but also the subsequent development of the dead animals into 

 germinating plants, in such a manner as to establish the truth of the 

 fact." (' Mag. of Nat. Hist.,' vol. i.) There are 9 species of the genus 

 Vaucheria found in Great Britain. 



VAUQUELINITE. [CHROMIUM; LEAD.] 



VEGETABLE BUTTERS. [BUTTERS, VEGETABLE.] 



VEGETABLE IVORY. [PUYTELEPHAS.] 



VEGETABLE KINGDOM. This term is applied collectively to 



4 G 



