pink, yellow varying from primrose to amber, vie with one another in vivid coloration, or contrasted, as happens in many species, with a warm tawny or a sombre slaty grey to say nothing of the delicate freckling of black and white, as minute as the markings of a moth's wing the whole set off by bands of white, producing an effect hardly equalled in any group. It is impossible within brief space to describe its glowing tints; but the plumage is further remarkable for the large size of its contour-feathers, which are extremely soft and so loosely seated as to come off in scores at a touch, and there is no down. The tail is generally a very characteristic feature, the rectrices, though in some cases pointed, being often curiously squared at the tip, and when this is the case they are usually barred ladderlike with white and black.[1] According to Gould, they are larger and more pointed in the young than in the old, and grow squarer and have the white bands narrower at each succeeding moult. He also asserts that in the species which have the wing-coverts freckled, the freckling becomes finer with age. So far as has been observed, the nidification of these birds is in holes of trees, wherein are laid without any bedding two roundish eggs, generally white, but certainly in one species (Quezal) tinted with bluish green.
The Trogons form a very well-marked Family, belonging to the multifarious group treated in the present series of articles as Picarix; but, instead of being (so far as is known) like all the rest of them and, as Prof. Huxley believed, "desmognathous," they have been shown by W. A. Forbes (Proc. Zool. Society, 1881, p. 836) to be "schizognathous " thus demonstrating, in the words of the latter, " that the structure of the palate has not that unique and peculiar significance that has been claimed for it in the classification of birds." Perhaps the explanation of this anomaly may lie in the fact that the Trogons are a very old form. The remains of one, T. gallicus, have been recognized by Prof. A. Milne-Edwards (Ois. foss. de la France, ii. p. 395, pi. 177, figs. 18-22) from the Miocene of the Allier, and it may not be too much to suppose that the schizognathous structure was more ancient than the desmognathous. Again too this fortunate discovery of that eminent palaeontologist seems to account for the remarkable distribution of the Trogons at the present day. While they chiefly abound, and have developed their climax of magnificence, in the tropical parts of the New World, they yet occur in the tropical parts of the Old. The species now inhabiting Africa, forming the group Hapalodcrma, can hardly be separated generically from those of the Neotropical Trogon, and the difference between the Asiatic forms, if somewhat greater, is still comparatively slight. It is plain then that the Trogons are an exceptionally persistent type; indeed in the whole Class few similar instances occur and perhaps none that can be called parallel. The extreme development of the type in the New World just noticed also furnishes another hint. While in some of the American Trogons (Pharomacriis, for instance) the plumage of the females is not very much less beautiful than that of the inales, there are others in which the hen birds retain what may be fairly deemed a more ancient livery, while the cocks flaunt in brilliant attire. Now the plumage of both sexes in all but one[2] of the Asiatic Trogons, Harpactes, resembles rather that of the young and of those females of the American species which are modestly clothed. The inference from this fact would seem to be that the general coloration of the Trogons prior to the establishment, by geographical estrangement, of the two types was a russet similar to that now worn by the adults of both sexes in the Indian region, and by a portion only of the females in the Neotropical. The Ethiopian type, as already said, very closely agrees with the American, and therefore would be likely to have been longer in connexion therewith. Again, while the adults of most of the American Trogons (Pharomacrus and Eiqrtilolis excepted) have the edges of the bill serrated, their young have them smooth or only with a single notch on either side near the tip, and this is observable in the Asiatic Trogons at all ages. At the same time the most distinctive features of the whole group, which are easily taken in at a glance, but are difficult to express briefly in words, are equally possessed by both branches of the Family, showing that they were in all likelihood for the possibility that the peculiarities may have been evolved apart is not to be over looked reached before the geographical sundering of these branches (whereby they are now placed on opposite sides of the globe) was effected.
It remains to say that about sixty species of Trogons are recognized, which Gould in the second edition of his Monograph of the Family (1875) divides into seven genera; but their characters are hardly laid down. Pharomacrus, Eupiilotis, and Trogon inhabit the mainland of tropical America, no species passing to the northward of the Rio Grande nor southward of the forest district of Brazil, while none occur on the west coast of Peru or Chili. Prionotelus and Tmetotroyon, each with one species, are peculiar respectively to Cuba and Hispaniola. The African form Hapaloderma has two species, one found only on the west coast, the other of more general range. The Asiatic Trogons, Harpactes (with eleven species according to the same authority), occur from Nepal to Malacca, in Ceylon, and in Sumatra, Java, and Borneo, while one species is peculiar to some of the Philippine Islands. (a. n.)
TROGUS, Cn. Pompeius, a Roman historian, nearly contemporary with Livy. Although the epitome of his historical writings by Justin, and a few fragments, are all that have come down to us, there is abundant reason to believe that he deserves a place in the history of Roman literature by the side of Sallust, Livy, and Tacitus. Of his life little is known. He was almost certainly of Greek descent. His grandfather served with Pompey in the war against Sertorius, and received through the influence of that general the Roman citizenship; hence the name Pompeius, which was adopted as a token of gratitude to the benefactor. The father of Trogus was an officer of Caesar. Trogus himself seems to have been a man of encyclopaedic knowledge. He wrote, after Aristotle and Theophrastus, books on the natural history of animals and plants, used by the elder Pliny, who calls Trogus "one of the most precise among authorities" (auctor ipse e severissimis). But the principal work of Trogus consisted of forty-four Libri Historiarum Philippicarum. This was a great history of the world, or rather of those portions of it which came under the sway of Alexander and his successors. The tale began with Ninus, the founder of Nineveh, and ceased at about the same point as Livy's great work, viz., 9 A.D. The last event recorded by the epitomator JUSTIN (q.v.} is the recovery of the Roman standards captured by the Parthians (20 B.C.). The history of Rome was treated as merely subsidiary to that of Greece and the East. The work was based upon the writings of Greek historians, such as Theopompus, Ephorus, Timseus, Polybius. It has been contended that Trogus did not gather together the information from the leading Greek historians for himself, but that it was already combined into a single book by some Greek, whom Trogus followed closely with some superficial errors. But the assumption appears improbable in itself, merely on a review of the remains of the historical writings, and is moreover inconsistent with what we know of the works in natural history, for which Trogus certainly went back to what were regarded in his time as first-hand authorities. It is generally admitted that Trogus had genuine qualifications for writing history, though he could not rid himself entirely of the faults of his authorities. His idea of history was more severe and less rhetorical than that followed by Sallust and Livy, whom he blamed for putting elaborate speeches in the mouths of the characters of whom they wrote. Yet his own Latin style had a vivid force which is still to be recognized in the extracts made by Justin. For the ancient history of the East, Trogus, even in the present mutilated state of his historical work, often proves to be an authority of great importance.
The chief modern editions are those of Gronovius (Leyden, 1719 and 1760); Frotscher(Leipsic, 1827-30); and Jeep (Leipsic, 1859 and 1862). In Engelmann's Bibliotheca Scriptorum Classicorum, ii., under Justin and Trogus, will be found a large number of references to scattered modern articles. Perhaps the most important is that of A. v. Gutschmid on the sources of the history of Trogus, in the second supplementary vol. of the Jahrlb. f. class. Philol. (Leipsic, 1857).
- ↑ In the Trogon of Cuba, Prionotelus, they are most curiously scooped out, as it were, at the extremity, and the lateral pointed ends diverge in a way almost unique among birds.
- ↑ Or two species if H. macloti be more than a local form of H. reinwardti.
of Pharomacrus auriceps to be a substance which he called "zooxanthine" (Comptes Rendus, 2d November 1857, xlv. p. 690).
