TSENG KUO-FAN (1811-1872), Chinese statesman and general, was born in 1811 in the province of Hunan, where he took in . succession the three degrees of Chinese scholarship. In 1843 he was appointed chief literary examiner in the province of Szechuen, and six years later was made junior vice-president of the board of rites. The Taiping rebels were overrunning Hunan, and Tseng was ordered to assist the governor of the province in raising a volunteer force, and on his own initiative he built a fleet of war junks, with which he attacked the rebels. His lieu tenants recovered the capital, Changsha, and destroyed the rebel fleet. Following up these victories of his subordinates, Tseng recaptured Wuchang and Hanyang, near Hankow, and was rewarded for his success by being appointed vice-president of the board of war. The rebels retook Wuchang and burnt the protect ing fleet. Tseng, however, succeeded in clearing the country round the Poyang lake, and subsequently in ridding the province of Kiangsu of the enemy. In 1857 he took supreme command in Cheh-kiang. Subsequently the rebels were driven westwards and Tseng then cleared the province of Ngan-hui of rebel bands.
In 186o he was appointed viceroy of the two Kiang provinces and Imperial war commissioner. At this time, and for some time previously, he had been fortunate in having the active support of Tso Tsung-t`ang, who at a later period recovered Kashgar for the emperor, and of Li Hung-Chang. In 1862 he became assistant grand secretary of State. At this time the Imperial forces, assisted by the "Ever-victorious Army," had checked the progress of the rebellion, and Tseng was able to carry out a scheme which he had long formulated of besieging Nanking, the rebel headquarters. While Gordon, with the help of Li Hung Chang, was clearing the cities on the lower waters of the Yangtse kiang, Tseng drew closer his besieging lines around the doomed city. In July 1864 the city fell into his hands, and he was rewarded with the rank and title of marquis.
Af ter the suppression of the Taipings the Nienfei rebellion, closely related to the former movement, broke out in Shantung, and Tseng was sent to quell it. He failed, and was relieved of his command by Li Hung-Chang, who succeeded him in the vice royalty of Chihli. Tseng died in 1872.
Tseng was a voluminous writer. His papers addressed to the throne and his literary disquisitions are held in high esteem by the scholars of China, who treasure as a memorial of a great and uncorrupt states man the edition of his collected works in 156 books, which was edited by Li Hung-Chang in 1876. (R. K. D.) the name given to any one of the twenty species of Glossina, a genus of African blood-sucking flies of the family Muscidae, order Diptera (q.v.). In appearance they are brownish insects banded or mottled with darker markings : they are somewhat larger than the house-fly and have a prominent proboscis projecting horizontally in front of the head. Their habit of resting with the wings closed flat, one over the other, on the back enables them to be distinguished from other blood sucking flies. The female insect does not lay eggs but brings forth at intervals a single fully-grown larva which is deposited on the ground, where it speedily conceals itself in some shady place and turns to a pupa. The flies abound where there is bush or forest,
often frequenting the margins of rivers, lakes and islands ; they are not found continuously but are restricted to areas known as fly belts. Both sexes are active blood suckers and are most troublesome during the hotter parts of the day, attacking both man and domestic animals. They are of great economic sig nificance because they act as carriers of the pathogenic organisms (trypanosomes) which are responsible for fatal diseases in man and animals. When a tsetse-fly alights on an infected subject and sucks its blood, numbers of the trypanosomes may be taken in at the same time. These tiny organisms require to undergo a de velopmental phase within the fly and when it is completed, are ready to pass into the blood of any man or animal upon which the fly happens to feed. In this manner the tsetse-fly Glossina pa/pa/is transmits Trypanosoma gambiense, the causal agent of sleeping sickness from man to man by means of its piercing mouth-parts, and in a similar fashion Glossina morsitans trans mits Trypanosoma rhodesiense, which is responsible for the more local or Rhodesian form of that disease. This same species of tsetse-fly is also the principal carrier of Trypanosoma brucei, which causes nagana disease among domestic animals. Five other kinds of tsetse-fly have been proved experimentally to be capable of transmitting trypanosomes, and it is probable that a number of species are natural carriers of the diseases mentioned.
The development of communications has probably been re sponsible for the spread of sleeping sickness from West Africa to eastern Central Africa where the population had acquired no im munity. In the five years 1901-06 it is stated that over 200,000 natives died of the complaint in Uganda, where it was previously unknown, and the local tsetse-flies up till then were believed to have been uninfected with the trypanosome. The island population of Lake Victoria Nyanza suffered most seriously from this out break. Among the various methods which have been tried to con trol the fly, the clearing of vegetation around villages, so as to make such localities unsuitable for the insect, is now receiving at tention. No feasible methods of luring or poisoning the insect are known, while the destruction of the concealed pupae presents great difficulties if carried out on a sufficiently extensive scale. The utilization of natural parasites has received some attention but at present offers little prospects of success. It has been proved experimentally that monkeys can be infected with the sleeping sickness trypanosome, and certain wild game, including antelopes, are regarded as functioning as "natural reservoirs" for trypano somes although they themselves apparently suffer little ill effects. For a discussion of this subject and all matters connected with the tsetse, see E. E. Austen and E. Hegh, Tsetse Flies (5922); also R. Newstead, Guide to the Study of the Tsetse Flies (1924). An account of the ravages of sleeping sickness is given by G. D. H.