forms the patient can be partially roused only to relapse again into a state of insensibility; in the deeper states, the patient cannot be roused at all, and such are met with in apoplexy, already described. Coma may arise abruptly in a patient who has presented no pre-existent indication of such a state occurring. Such a condition is called primary coma, and may result from the following causes:—(1) concussion, compression or laceration of the brain from head injuries, especially fracture of the skull; (2) from alcoholic and narcotic poisoning; (3) from cerebral haemorrhage, embolism and thrombosis, such being the causes of apoplexy. Secondary coma may arise as a complication in the following diseases:—diabetes, uraemia, general paralysis, meningitis, cerebral tumour and acute yellow atrophy of the liver; in such diseases it is anticipated, for it is a frequent cause of the fatal termination. The depth of insensibility to stimulus is a measure of the gravity of the symptom; thus the conjunctival reflex and even the spinal reflexes may be abolished, the only sign of life being the respiration and heart-beat, the muscles of the limbs being sometimes perfectly flaccid. A characteristic change in the respiration, known as Cheyne-Stokes breathing occurs prior to death in some cases; it indicates that the respiratory centre in the medulla is becoming exhausted, and is stimulated to action only when the venosity of the blood has increased sufficiently to excite it. The breathing consequently loses its natural rhythm, and each successive breath becomes deeper until a maximum is reached; it then diminishes in depth by successive steps until it dies away completely. The condition of apnoea, or cessation of breathing, follows, and as soon as the venosity of the blood again affords sufficient stimulus, the signs of air-hunger commence; this altered rhythm continues until the respiratory centre becomes exhausted and death ensues.
Coma Vigil is a state of unconsciousness met with in the algide stage of cholera and some other exhausting diseases. The patient’s eyes remain open, and he may be in a state of low muttering delirium; he is entirely insensible to his surroundings, and neither knows nor can indicate his wants.
There is a distinct word “coma” (Gr. κόμη, hair), which is used in astronomy for the envelope of a comet, and in botany for a tuft.
COMA BERENICES (“Berenice’s Hair”), in astronomy,
a constellation of the northern hemisphere; it was first mentioned
by Callimachus, and Eratosthenes (3rd century B.C.), but is not
included in the 48 asterisms of Ptolemy. It is said to have been
named by Conon, in order to console Berenice, queen of Ptolemy
Euergetes, for the loss of a lock of her hair, which had been
stolen from a temple to Venus. This constellation is sometimes,
but wrongly, attributed to Tycho Brahe. The most interesting
member of this group is 24 Comae, a fine, wide double star,
consisting of an orange star of magnitude 512, and a blue star,
magnitude 7.
COMACCHIO, a town of Emilia, Italy, in the province of
Ferrara, 30 m. E.S.E. by road from the town of Ferrara, on the
level of the sea, in the centre of the lagoon of Valli di Comacchio,
just N. of the present mouth of the Reno. Pop. (1901) 7944
(town), 10,745 (commune). It is built on no less than thirteen
different islets, joined by bridges, and its industries are the
fishery, which belongs to the commune, and the salt-works.
The seaport of Magnavacca lies 4 m. to the east. Comacchio
appears as a city in the 6th century, and, owing to its position
in the centre of the lagoons, was an important fortress. It was
included in the “donation of Pippin”; it was taken by the
Venetians in 854, but afterwards came under the government
of the archbishops of Ravenna; in 1299 it came under the
dominion of the house of Este. In 1508 it became Venetian,
but in 1597 was claimed by Clement VIII. as a vacant fief.
COMANA, a city of Cappadocia [frequently called Chryse or
Aurea, i.e. the golden, to distinguish it from Comana in Pontus;
mod. Shahr], celebrated in ancient times as the place where the
rites of Mā-Enyo, a variety of the great west Asian Nature-goddess,
were celebrated with much solemnity. The service
was carried on in a sumptuous temple with great magnificence
by many thousands of hieroduli (temple-servants). To defray
expenses, large estates had been set apart, which yielded a more
than royal revenue. The city, a mere apanage of the temple,
was governed immediately by the chief priest, who was always
a member of the reigning Cappadocian family, and took rank
next to the king. The number of persons engaged in the service
of the temple, even in Strabo’s time, was upwards of 6000, and
among these, to judge by the names common on local tombstones,
were many of Persian race. Under Caracalla, Comana
became a Roman colony, and it received honours from later
emperors down to the official recognition of Christianity. The
site lies at Shahr, a village in the Anti-Taurus on the upper
course of the Sarus (Sihun), mainly Armenian, but surrounded
by new settlements of Avshar Turkomans and Circassians. The
place has derived importance both in antiquity and now from
its position at the eastern end of the main pass of the western
Anti-Taurus range, the Kuru Chai, through which passed the
road from Caesarea-Mazaca (mod. Kaisarieh) to Melitene
(Malatia), converted by Septimius Severus into the chief military
road to the eastern frontier of the empire. The extant remains
at Shahr include a theatre on the left bank of the river, a fine
Roman doorway and many inscriptions; but the exact site
of the great temple has not been satisfactorily identified. There
are many traces of Severus’ road, including a bridge at Kemer,
and an immense number of milestones, some in their original
positions, others in cemeteries.
See P. H. H. Massy in Geog. Journ. (Sept. 1905); E. Chantre, Mission en Cappadocie (1898). (D. G. H.)
COMANA (mod. Gumenek), an ancient city of Pontus, said
to have been colonized from Comana in Cappadocia. It stood
on the river Iris (Tozanli Su or Yeshil Irmak), and from its
central position was a favourite emporium of Armenian and
other merchants. The moon-goddess was worshipped in the
city with a pomp and ceremony in all respects analogous to those
employed in the Cappadocian city. The slaves attached to the
temple alone numbered not less than 6000. St John Chrysostom
died there on the way to Constantinople from his exile at Cocysus
in the Anti-Taurus. Remains of Comana are still to be seen
near a village called Gumenek on the Tozanli Su, 7 m. from Tokat,
but they are of the slightest description. There is a mound;
and a few inscriptions are built into a bridge, which here spans
the river, carrying the road from Niksar to Tokat. (D. G. H.)
COMANCHES, a tribe of North American Indians of Shoshonean
stock, so called by the Spaniards, but known to the
French as Padoucas, an adaptation of their Sioux name, and
among themselves nimenim (people). They number some 1400,
attached to the Kiowa agency, Oklahoma. When first met by
Europeans, they occupied the regions between the upper waters
of the Brazos and Colorado on the one hand, and the Arkansas
and Missouri on the other. Until their final surrender in 1875
the Comanches were the terror of the Mexican and Texan
frontiers, and were always famed for their bravery. They were
brought to nominal submission in 1783 by the Spanish general
Anza, who killed thirty of their chiefs. During the 19th century
they were always raiding and fighting, but in 1867, to the
number of 2500, they agreed to go on a reservation. In 1872
a portion of the tribe, the Quanhada or Staked Plain Comanches,
had again to be reduced by military measures.
COMAYAGUA, the capital of the department of Comayagua in central Honduras, on the right bank of the river Ulua, and on the interoceanic railway from Puerto Cortes to Fonseca Bay. Pop. (1900) about 8000. Comayagua occupies part of a fertile valley, enclosed by mountain ranges. Under Spanish rule it was a city of considerable size and beauty, and in 1827 its inhabitants numbered more than 18,000. A fine cathedral, dating from 1715, is the chief monument of its former prosperity, for most of the handsome public buildings erected in the colonial period have fallen into disrepair. The present city chiefly consists of low adobe houses and cane huts, tenanted by Indians. The university founded in 1678 has ceased to exist, but there is a school of jurisprudence. In the neighbourhood are many ancient Indian ruins (see Central America: Archaeology).
Founded in 1540 by Alonzo Caceres, who had been instructed
