[1] _Bull. Amer. Mus. Nat. Hist._ vol. xii. (1899).
[2] _Proc. Zool. Soc._ (London, 1904), vol. ii.
CHIRU, a graceful Tibetan antelope (_Pantholops Hodgsoni_), of which the
bucks are armed with long, slender and heavily-ridged horns of an
altogether peculiar type, while the does are hornless. Possibly this
handsome antelope may be the original of the mythical unicorn, a single
buck when seen in profile looking exactly as if it had but one long
straight horn. Although far from uncommon, chiru are very wary, and
consequently difficult to approach. They are generally found in small
parties, although occasionally in herds. They inhabit the desolate
plateau of Tibet, at elevations of between 13,000 and 18,000 ft., and,
like all Tibetan animals, have a firm thick coat, formed in this
instance of close woolly hair of a grey fawn-colour. The most peculiar
feature about the chiru is, however, its swollen, puffy nose, which is
probably connected with breathing a highly rarefied atmosphere. A second
antelope inhabiting the same country as the chiru is the goa (_Gazella
picticaudata_), a member of the gazelle group characterized by the
peculiar form of the horns of the bucks and certain features of
coloration, whereby it is markedly distinguished from all its kindred
save one or two other central Asian species. The chiru, which belongs to
the typical or antilopine section of antelopes, is probably allied to
the saiga. (R. L.*)
CHIRURGEON, one whose profession it is to cure disease by operating with
the hand. The word in its original form is now obsolete. It derives from
the Mid. Eng. _cirurgien_ or _sirurgien_, through the Fr. from the Gr.
[Greek: cheirourgos], one who operates with the hand (from [Greek:
cheir], hand, [Greek: ergon], work); from the early form is derived the
modern word "surgeon." "Chirurgeon" is a 16th century reversion to the
Greek origin. (See SURGERY.)
CHISEL (from the O. Fr. _cisel_, modern _ciseau_, Late Lat. _cisellum_,
a cutting tool, from _caedere_, to cut), a sharp-edged tool for cutting
metal, wood or stone. There are numerous varieties of chisels used in
different trades; the carpenter's chisel is wooden-handled with a
straight edge, transverse to the axis and bevelled on one side; stone
masons' chisels are bevelled on both sides, and others have oblique,
concave or convex edges. A chisel with a semicircular blade is called a
"gouge." The tool is worked either by hand-pressure or by blows from a
hammer or mallet. The "cold chisel" has a steel edge, highly tempered to
cut unheated metal. (See TOOL.)
CHISLEHURST, an urban district in the Sevenoaks parliamentary division
of Kent, England, 11-1/4 m. S.E. of London, by the South-Eastern &
Chatham railway. Pop. (1901) 7429. It is situated 300 ft. above
sea-level, on a common of furze and heather in the midst of picturesque
country. The church of St Nicholas (Perpendicular with Early English
portions, but much restored) has a tomb of the Walsingham family, who
had a lease of the manor from Elizabeth; Sir Francis Walsingham, the
statesman, being born here in 1536. Another statesman of the same age,
Sir Nicholas Bacon, was born here in 1510. Near the church is an ancient
cockpit. The mortuary chapel attached to the Roman Catholic church of St
Mary was built to receive the body of Napoleon III., who died at Camden
Place in 1873; and that of his son was brought hither in 1879. Both were
afterwards removed to the memorial chapel at Farnborough in Hampshire.
Camden Place was built by William Camden, the antiquary, in 1609, and in
1765 gave the title of Baron Camden to Lord Chancellor Pratt. The house
was the residence not only of Napoleon III., but of the empress Eugenie
and of the prince imperial, who is commemorated by a memorial cross on
Chislehurst Common. The house and grounds are now occupied by a golf
club. There are many villa residences in the neighbourhood of
Chislehurst.
CHISWICK, an urban district in the Ealing parliamentary division of
Middlesex, England, suburban to London, on the Thames, 71/2 m. W. by S. of
St Paul's cathedral. Pop. (1901) 29,809. The locality is largely
residential, but there are breweries, and the marine engineering works
of Messrs Thornycroft on the river. Chiswick House, a seat of the duke
of Devonshire, is surrounded by beautiful grounds; here died Fox (1806)
and Canning (1827). The gardens near belonged till 1903 to the Royal
Horticultural Society. The church of St Nicholas has ancient portions,
and in the churchyard is the tomb of William Hogarth the painter, with
commemorative lines by David Garrick. Hogarth's house is close at hand.
Chiswick Hall, no longer extant, was formerly a country seat for the
masters and sanatorium for the scholars of Westminster school. Here in
1811 the Chiswick Press was founded by Charles Whittingham the elder, an
eminent printer (d. 1840).
CHITA, a town of east Siberia, capital of Transbaikalia, on the Siberian
railway, 500 m. E. of Irkutsk, on the Chita river, half a mile above its
confluence with the Ingoda. Pop. (1883) 12,600; (1897) 11,480. The
Imperial Russian Geographical Society has a museum here. Several of the
palace revolutionaries, known as Decembrists, were banished to this
place from St Petersburg in consequence of the conspiracy of December
1825. The inhabitants support themselves by agriculture and by trade in
furs, cattle, hides and tallow bought from the Buriats, and in
manufactured wares imported from Russia and west Siberia.
CHITALDRUG, a district and town in the native state of Mysore, India.
The district has an area of 4022 sq. m. and a population (1901) of
498,795. It is distinguished by its low rainfall and arid soil. It lies
within the valley of the Vedavati or Hagari river, mostly dry in the hot
season. Several parallel chains of hills, reaching an extreme height of
3800 ft., cross the district; otherwise it is a plain. The chief crops
are cotton and flax; the chief manufactures are blankets and cotton
cloth. The west of the district is served by the Southern Mahratta
railway. The largest town in the district is Davangere (pop. 10,402).
The town of CHITALDRUG, which is the district headquarters (pop. 1901,
5792), was formerly a military cantonment, but this was abandoned on
account of its unhealthiness. It has massive fortifications erected
under Hyder Ali and Tippoo Sahib towards the close of the 18th century;
and near it on the west are remains of a city of the 2nd century A.D.
CHITON, the name[1] given to fairly common littoral animals of rather
small size which belong to the phylum Mollusca, and, in the possession
of a radula in the buccal cavity, resemble more especially the
Gastropoda. Their most important characteristic in comparison with the
latter is that they are, both in external and internal structure,
bilaterally symmetrical. The dorsal integument or mantle bears, not a
simple shell, but eight calcareous plates in longitudinal series
articulating with each other. The ventral surface forms a flat creeping
"foot," and between mantle and foot is a pallial groove in which there
is on each side a series of gills. Originally the Chitons were placed
with the limpets, _Patella_, in Cuvier's _Cyclobranchia_, an order of
the Gastropoda. In 1876 H. von Jhering demonstrated the affinities of
_Neomenia_ and _Chaetoderma_, vermiform animals destitute of shell, with
the Chitons, and placed them all in a division of worms which he named
Amphineura. The discovery by A.A.W. Hubrecht in 1881 of a typical
molluscan radula and odontophore in a new genus _Proneomenia_, allied to
_Neomenia_, showed that the whole group belonged to the Mollusca. E. Ray
Lankester (_Ency. Brit._, 9th ed., 1883) placed them under the name
Isopleura as a subclass of Gastropoda. Paul Pelseneer (1906) raised the
group to the rank of a class of Mollusca, under von Jhering's name
Amphineura.
The Amphineura are divided into two orders: (1) the Polyplacophora, or
Chitons; (2) the Aplacophora, or forms without shells, _Neomenia_,
_Chaetoderma_ and their allies.