508 



PYRUS-RACOON. 



who separated them the first, was only guided by the 

 want of varices, and he did not distinguish the pyrula 

 from the f'usus, from which it widely differs ; the 

 spire of the former being short and very much de- 

 pressed, and the last whorl extremely large and veri- 

 tricose, frequently extending at its margin above the 

 elevated point of the spire, and giving the shells of 

 this genus the form of a fi<r or pear, which never occurs 

 with the genus fusus. The pyrulye are in shaye sub- 

 pyriforrn, channelled at the base, without varices ; 

 columella smooth, and without a notch at the lip, to 

 which may be added, that the edge of the aperture is 

 most generally crenulated. The substance of this 

 shell is very thin, semi-transparent, and with internal 

 and external slight transverse ribs, interrupted by the 

 sutures formed at the previous stages of the growth 

 of the opening ; they possess most of them a very 

 wide umbilicus, and the aperture is closed by an 

 ovate pear-shaped horny opereulum. The animal is 

 at present undescribed. About twenty-eight species 

 are known, in a recent state, only one or two of 

 which inhabit the Northern seas. Some fossil spe- 

 cies are described. 



PYRUS (Lirinseus). A genus of ornamental and 

 fruit-trees, the latter forming the chief of our orchard 

 fruit, viz. the pear and apple. The service, white- 

 beam, medlar, Siberian crab, &c., all belong to this 

 genus, and to the natural order Rosaces. The varie- 

 ties of these different species are most valuable, and 

 are propagated by grafting on the common wild 

 crab, or on their own seedlings. 



PYURA (Molina). A species of Ascidea, evi- 

 dently forming the connecting link in malacology 

 between the simple and aggregated Ascideae. 



QUADRUMANA. Animals having the extre- 

 mities of all their limbs formed like hands, including 

 apes, baboons, monkeys, and a few others, for which 

 see those articles, and the general article MAM- 

 MALIA. 



QUARTZ. There are few mineral productions 

 more beautiful or diversified than rock crystal or 

 quartz. It is of great specific gravity, and its hard- 

 ness fits it for the most enduring labours of man. It 

 is frequently milk white, and of a more or less gra- 

 nular texture. The Sugar-Loaf Mountains near 

 Dublin, the Paps of Jura in ArgyJeshire. and some 

 of the mountains of Sutherland and Caithness present 

 well-marked instances of this geological formation. 

 Brown and yellow crystals of quartz are found in 

 great beauty in the mountains of Cairn Gorm in 

 Scotland, and are much admired by the jewellers : 

 they are sometimes called topazes. The purple 

 quartz owes its beautiful colour to the presence of a 

 little iron and manganese, and the rose quartz to the 

 action of manganese alone. 



QUASSIA (Willdenow). A South American 

 tree having diandrous flowers, and belonging to the 

 natural order Simarubacece. The generic name com- 

 memorates a negro of that name, who first used the 

 bark as a medicine, and administered it with success 

 in the treatment of malignant fevers endemical to 

 Surinam. Quassia bark is sometimes surreptitiously 

 used instead of hops, but a penalty attaches to the 

 public brewer who uses it. It is neither so pleasant 

 in beer, nor will the beer keep so well as if made of 

 hops. 



QUEEN BEE. The name usually given to the 

 only fully developed female insect in the community 



of the hive, all the other inhabitants being either 

 males, or drones, i. e. females, whose development has 

 been rendered partially abortive by reason of a certain 

 peculiarity of food. See the article BEE. 



QUERCUS (Linnajus). Of all hardy forest trees 

 this genus is perhaps the most interesting as well for 

 ship and other building, as for its grandeur in land- 

 scape and value of its fruit as pannage. The oak 

 bears monoecious llowers, and belongs to the natural 

 order Amentacecc. There are already described sixty- 

 two species and above twenty varieties, all natives of 

 Europe and America. Some of them are shrubs, but 

 the great majority are useful timber-trees, and at the 

 same time highly ornamental. They are all propa- 

 gated by seed when they can be procured, though 

 some of the choice American kinds are increased by 

 engrafting on the common British oak. There are two 

 species (or one species and one variety) in the native 

 woods of Britain ; and it is somewhat remarkable 

 that it is not yet (1837) clearly ascertained which of 

 the two is the true naval oak of this country. The 

 botanical difference between the Q. robur of Linnaeus 

 and the Q. pedunculata of Wildlenow, is the circum- 

 stance (perhaps accidental) of the latter bearing its 

 acorns on footstalks, while the former has its acorns 

 sessile, that is, sitting close upon the bearing twigs. 

 The pedunculata is a more elegant and freer growing 

 tree ; but the robur or sessile fruited has more the 

 tufted and picturesque character of the British oak. 

 That the timber of one of these is superior in dura- 

 bility to the other is well known to builders, but the 

 best of the two has not yet been identified ; some 

 being of one opinion, and others of another. The 

 authority of mere botanists is of no value in this 

 question ; and from the evidence of an eminent 

 builder, Mr. Atkinson, it appears that the Q. robur 

 yields the superior timber. This is a question of 

 the greatest importance to nurserymen who raise 

 seedlings for sale. 



Besides timber, the bark is most valuable for tan- 

 ning leather and cordage. The Q. .tuber yields the 

 material for the manufacture of corks ; the Q. thic- 

 toria supplies the quercitron, and the Q. cocci/era the 

 galls for dying. 



QUINCE is the fruit of the Cydunia vulgarix of 

 Tournefort. A common orchard fruit used by the 

 cook and confectioner. 



QUINOA. The specific name of a Chinapodium 

 indigenous and cultivated in Peru for its seeds, which 

 are used in that country as millet is in Europe. It 

 has been introduced here as an economical plant, but 

 does not answer. 



QUISQUALIS (Linnasus). A genus of climbing- 

 shrubs, natives of Africa and the East Indies. The 

 flowers are decandrous, and the genus belongs to 

 Coinbretacece. The species (except Q. indica) are 

 not much known in our collections; but they seem 

 to be easy of culture, striking root readily by 

 cuttings. 



QUIVISIA (Cavanille). A pretty genus be- 

 longing to MehacecR. It is a stove plant introduced 

 from the Isle of France, and succeeds well in heath- 

 mould and sand, and in which soil cuttings strike 

 roots freely. 



RACOON (Procyon). A genus of plantigrade 

 carnivorous mammalia, having some resemblance to 

 the bears, but still sufficiently distinct for being 

 regarded as a separate genus. Their cheek-teeth are 



