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Rh of life. The picturesque and even elegant national costume shows in its ornamentation and general style decided Japanese influence, due no doubt to long-continued intercourse with that nation at some period previous to the spread of the race from the Amur valley to Siberia. Many of the Tungus tribes have been baptized, and are, therefore, reckoned as “Greek Christians”; but Russian orthodoxy has not penetrated far below the surface, and most of them are still at heart Shamanists and nature-worshippers, secretly keeping the teeth and claws of wild animals as idols or amulets, and observing Christian rites only under compulsion. But, whether Christians or pagans, all alike are distinguished above other Asiatics, perhaps above all other peoples, for their truly noble moral qualities. All observers describe them as “cheerful under the most depressing circumstances, persevering, open-hearted, trustworthy, modest yet self-reliant, a fearless race of hunters, born amidst the gloom of their dense pine forests, exposed from the cradle to every danger from wild beasts, cold and hunger. Want and hardships of every kind they endure with surprising fortitude, and nothing can induce them to take service under the Russians or quit their solitary woodlands” (Keane's Asia, p. 479). Their numbers are steadily decreasing owing to the ravages of small-pox, scarlet fever, and especially famine, their most dreaded enemy. Their domain is also being continually encroached upon by the aggressive Yakuts from the north and east, and from the south by the Slavs, now settled in compact bodies in the province of Irkutsk about the upper course of the Yenisei. It is remarkable that, while the Russians often show a tendency to become assimilated to the Yakuts, the most vigorous and expansive of all the Siberian peoples, the Tunguses everywhere yield before the advance of their more civilized neighbours or become absorbed in the surrounding Slav communities. In the Amur valley the same fate is overtaking the kindred tribes, who are disappearing before the great waves of Chinese migration from the south and Russian encroachments both from the east and west.

See L. Adam, Grammaire de la langue toungouse (Paris, 1874); C. Hickisch, Die Tungusen (St Petersburg, 1879); L. Schrenck, Reisen und Forschungen im Amurlande (St Petersburg, 1881-1891); Mainov, Niekotorya dannyia (Irkutsk, 1898).  TUNIC (O. Eng. tunice, tunical, taken, before the Norman conquest, directly from Lat. tunica, of which the origin is unknown), properly the name given in Latin to the principal undergarment of men and women, answering to the chiton of the Greeks, and covered by the outer garment, the palla (Gr. ), in the case of women, and by the peculiar Roman garment, the toga, in the case of men. The male tunica differed from the in usually having short sleeves (see further : § Ancient Greek and Roman). The term, more often in the form “tunicle” (Lat. dim. tunicula), is applied, in ecclesiastical usage, to a vestment worn over the alb by the sub-deacon in the celebration of the Mass. In general current usage it is used of any loose short garment, girt at the waist and reaching from the neck to some distance above the knee. It is thus the name of the fatigue coat of a soldier of the British army. There are numerous uses of “tunic” or “tunica” in anatomy, zoology and botany in the sense of a covering or integument.  TUNICATA. This group of marine animals was formerly regarded as constituting, along with the Polyzoa and the Brachiopoda, the invertebrate class Molluscoidea. It is now known to be a degenerate branch of the Chordata, and to be more nearly related to the Vertebrata than to any group of the Invertebrata. The Tunicata are found in all seas, from the littoral zone down to abyssal depths. They occur either fixed or free, solitary, aggregated or in colonies. The fixed forms are the “simple” and “compound” Ascidians. The colonies are produced by budding and the members are conveniently known as Ascidiozooids. Some Tunicata undergo alternation of generations, and most of them show a retrograde metamorphosis in their life-history.

More than two thousand years ago Aristotle gave a short account of a simple Ascidian under the name of Tethyum. Schlosser and Ellis, in a paper on Botryllus, published in the Philosophical Transactions of the Royal Society for 1756, first brought the compound Ascidians into notice; but it was not until the commencement of the 19th century, as a result of the careful anatomical investigations of G. Cuvier (1) upon the simple Ascidians and of J. C. Savigny (2) upon the compound, that the close relationship between these two

groups of the Tunicata was conclusively demonstrated. Lamarck (3) in 1816 instituted the class Tunicata, which he placed between the Radiara and the Vermes in his system of classification. The Tunicata included at that time, besides the simple and the compound Ascidians, the pelagic forms Pyrosoma, which had been first made known by F. Péron in 1804, and Salpa, described by P. Forskål in 1775.

A. v. Chamisso, in 1819, made the important discovery that Salpa in its life-history passes through the series of changes which were afterwards more fully described by J. J. S. Steenstrup in 1842 as “alternation of generations”; and a few years later Kuhl and Van Hasselt's investigations upon the same animal resulted in the discovery of the alternation in the directions in which the wave of contraction passes along the heart and in which the blood circulates through the body. It has since been found that this observation holds good for all groups of the Tunicata. In 1826 H. Milne-Edwards and Audouin made a series of observations on living compound Ascidians, and amongst other discoveries they found the free-swimming tailed larva, and traced its development into the young Ascidian.

In 1845 Carl Schmidt (6) first announced the presence in the test of some Ascidians of “tunicine,” a substance very similar to cellulose, and in the following year Löwig and A. v. Kölliker (7) confirmed the discovery and made some additional observations upon this substance and upon the structure of the test in general. T. H. Huxley (8), in an important series of papers published in the Transactions of the Royal and Linnean Societies of London from 1851 onwards, discussed the structure, embryology and affinities of the pelagic Tunicates Pyrosoma, Salpa, Doliolum and Appendicularia. These important forms were also investigated about the same time by C. Gegenbaur, C. Vogt, H. Müller, A. Krohn and F. S. Leuckart. The most important epoch in the history of the Tunicata is the date of the publication of A. Kowalevsky's celebrated memoir upon the development of a simple Ascidian (9). The tailed larva had been previously investigated; but its minute structure had not been sufficiently examined, and the meaning of what was known of it had not been understood. It was reserved for Kowalevsky in 1866 to demonstrate the striking similarity in structure and in development between the larval Ascidian and the vertebrate embryo. He showed that the relations between the nervous system, the notochord and the alimentary canal are the same in the two forms, and have been brought about by a very similar course of embryonic development. This discovery clearly indicated that the Tunicata are closely allied to Amphioxus and the Vertebrata, and that the tailed larva represents the primitive or ancestral form from which the adult Ascidian has been evolved by degeneration, and this led naturally to the view usually accepted at the present day, that the group is a degenerate side-branch from the lower end of the phylum Chordata, which includes the Tunicata (Urochorda), Balanoglossus, &c. (Hemichorda), Amphioxus (Cephalochorda) and the Vertebrata. Kowalevsky's great discovery has since been confirmed and extended to all other groups of the Tunicata by C. v. Kupffer (12), A. Giard (13 and 15), an others.

In 1872 H. Fol (14) added largely to the knowledge of the Appendiculariidae, and Giard (15) to that of the compound Ascidians. The most important additions which have been made to the latter since have been those described by Von Drasche (16) from the Adriatic and those discovered by the “Challenger” and other expeditions (17). The structure and the systematic arrangement of the simple Ascidians have been mainly discussed of recent years by J. Alder and A. Hancock (18), C. Heller (19), H. de Lacaze-Duthiers (20), M. Traustedt (21), L. Roule, R. Hartmeyer, C. P. Sluiter, W. Michaelsen and W. A. Herdman (17, 22). In 1874 Ussoff (23) investigated the minute structure of the nervous system and of the underlying gland (first discovered by Hancock), and showed that the duct communicates with the front of the bronchial sac or pharynx by an aperture in the dorsal (or “olfactory”) tubercle. In 1880 C. Julin (24) drew attention to the similarity in structure and relations between this gland and the hypophysis cerebri of the vertebrate brain, and insisted upon their homology. M. M. Metcalf has since added to our knowledge of these structures. The Thaliacea have of late years been the subject of several very important memoirs. The researches of F. Todaro, W. K. Brooks (25), W. Salensky (26), O. Seeliger, Korotneff and others have elucidated the embryology, the gemmation and the life-history of the Salpidae; and K. Grobben, Barrois (27), and more especially Uljanin (28), have elaborately worked out the structure and the details of the complicated life history of the Doliolidae. Finally, we owe to the successive memoirs of J. Hjort, O. Seeliger, W. E. Ritter, E. van Beneden, C. Julin, C. P. Sluiter, R. Hartmeyer and others the description of many new forms and much information as to the development and life-history of the group.

The new forms described from Puget Sound and Alaska have drawn renewed attention to the similarity of the fauna in that region of the North Pacific and the fauna of north-west Europe. There is probably a common circumpolar Tunicate fauna which sends extensions downwards in both Atlantic and Pacific. As the result of the careful quantitative work of the German Plankton expedition, A. Borgert thinks that the temperature of the water has more to do with both the horizontal and the vertical distribution of pelagic