Page:The American Cyclopædia (1879) Volume VII.djvu/623

 GANGLION 611 koomiah and the muggar, inhabit both fresh and salt water, and prey with great boldness upon men, and upon animals wild and domestic. The Ganges is the main artery of an exten- sive and intricate natural system of Himalay- an drainage. Of the 19 or 20 affluents which it receives after leaving the mountains, 12 are said to be larger than the Khine. . Considered as a whole, the Gangetic plain is one of the finest and most fertile countries in the world. It is the most populous portion of India, and that in which agriculture is most flourishing. The rainfall of the Ganges basin above Allaha- bad, however, being but little more than 30 in., the agricultural interests of that region required a permanent system of irrigation, to supply which the Ganges canal was construct- ed. It was commenced in 1848, opened in 1854, and is the greatest work of irrigation ever completed. It extends in a southeasterly direction from Hurdwar to Oawnpore, travers- ing the country between the Ganges and the Jumna, with numerous offshoots which, like the main channel, are adapted for internal navi- gation as well as for irrigation. The length of the main channel is 348 in., and the branches are 306 m. long. The distributaries have an aggregate length of 3,078 m., and water 767,- 000 acres in 5,061 villages. In 1871-'2 the profits of the Ganges canal were 66,234, being 2'78 per cent, on the capital. The Ganges oc- cupies a prominent place in Hindoo mythology. It is revered as the most sacred of rivers by the Hindoos, who convey its sanctified waters to all parts of India for use in ceremonial ablu- tions. There are particular places along the banks whence it is regarded as most desirable to obtain the water, but that from Benares is reverenced as the holiest of all. Here and elsewhere numerous and handsome flights of 'stone steps, called ghauts, render access to the river easy. The principal cities and towns on the banks of the Ganges are Furruckabad, Cawnpore, Allahabad, Benares, Ghazepoor, and Patna ; and on the Hoogly branch, Calcutta. GANGLION (Gr. yayyAwv, a little swelling), in anatomy, a small rounded or elongated ner- vous mass, of a reddish gray color, situated in the course of the nerves. There are two kinds of nervous ganglia, one forming part of the cranial system of nerves, the other part of the sympathetic system ; the first kind are situated near the origins of many of the cra- nial and of all the vertebral nerves, and on the rior or sensory root of the latter; the second are generally placed along the sides of the anterior surface of the spinal column, from the head to the coccyx, the two great semilunar and cardiac ganglia coming near the median line. They are composed of two sub- s, one white like the medullary substance of the brain, the other reddish gray, somewhat resembling the cerebral cortical substance; the internal medullary filaments are the con- tinuation of the nerve upon which the ganglion is situated. The sympathetic system of gan- glia is considered by some as a series of more or less independent centres, giving off nerves to the organs of nutrition or communicating branches to the cerebro-spinal system ; accord- ing to others, these ganglia and their associated nerves form a special system with numerous ramifications, the sympathetic system presiding over the involuntary contractions of the heart and digestive apparatus, and all the processes concerned in secretion, nutrition, and exhala- tion, and in disease conveying different sympa- thetic phenomena from one part of the organ- ism to another. Strictly speaking, all the ner- vous centres in the highest vertebrates may be called ganglia; even the hemispheres of the huinan^ brain may properly be styled cerebral ganglia. The principal ganglia of the head are the ophthalmic, which sends branches to the iris and the vascular apparatus of the eyeball ; the otic, intimately connected with the organ of hearing ; Meckel's or the spheno -palatine, ministering to the senses of smell and taste ; the submaxillary, whose branches proceed Tal- most entirely to the gland of that name ; the Gasserian, of the fifth pair of nerves ; and those near the roots of the pneumogastric and glos- sopharyngeal. In the neck are the superior, middle, and inferior ganglia of the sympathetic, and the origins of the cardiac plexus which supplies the heart ; in the chest, the 12 tho- racic ganglia on each side, from which originate the splanchnic nerves which go to join the semilunar ganglia and the solar plexus ; in the abdomen, the latter sends branches which ac- company all the divisions of the aorta. There are besides these the lumbar and sacral ganglia on each side of the spine, distributing their branches to the^organs in the pelvis. The so- called lymphatic ganglia are glandular, and not nervous masses. In the invertebrata ganglia are the highest form of nervous centres, and occur either isolated or connected together by single or double longitudinal cords ; they per- form the functions both of the cerebral and spinal centres of the higher animals. In sur- gery, a ganglion is a small indolent fluctuating tumor, developed in the course of the tendons, containing a semi-fluid secretion enclosed in a cyst, generally communicating with the tendi- nous sheath. It is a dropsy of the synovial sheath, caused by friction, some wrench or ten- sion of the tendon, or the sequence of some rheumatic or gouty disease ; the light of a can- dle may be seen through it. The most com- mon situation is about the wrist and fingers, though it may occur in the course of any ten- don. When there is no inflammation, the best treatment is to puncture the tumor by the sub- cutaneous method, in order that the contained fluid may escape into the surrounding areolar tissue and be absorbed ; pressure and cold ap- plications should then be applied. If this fail, stimulating liniments and even blisters may be tried, to induce absorption. When unconnect- ed with a tendinous sheath, the tumor may be dissected out, punctured like an abscess, or