from the scarlet-crimson of its wing-coverts and its white spotted
primaries. Its bright hue is hardly visible when the bird is at rest,
and it then presents a dingy appearance of grey and black. It is
a species of wide range, extending from Spain to China; and, though
but seldom leaving its cliffs, it has wandered even so far as England.
Merrett (Pinax, p. 177) in 1667 included it as a British bird, and the
correspondence between Marsham and Gilbert White (Proc. Norf.
and Norw. Nat. Society, ii. 180) proves that an example was shot in
Norfolk, on the 30th of October 1792; while another is reported
(Zoologist, 2nd series, p. 4839) to have been killed in Lancashire on
the 8th of May 1872.
The passerine family Certhiidae contains a number of genera of birds to which the general name “creeper” is applied; they occur in North America, Europe and Asia, the greater part of Africa, and Australia and New Guinea. (A. N.)
TREE-FERN. In old and well-grown specimens of some of the familiar ferns of temperate climates the wide-spreading crown of fronds may be observed to rise at the distance often of a good many inches above the ground, and from a stem of considerable thickness. The common male fern Lastraea (Filix-mas) affords the commonest instance of this; higher and thicker trunks are, however, occasionally presented by the royal fern (Osmunda regalis), in which a height of 2 ft. may be attained, and this with very considerable apparent thickness, due, however, to the origin and descent of a new series of adventitious roots from the bases of each annual set of fronds. Some tropical members and allies of these genera become more distinctly tree-like, e.g. Toeda; Pteris also has some sub-arboreal forms. Oleandra is branched and shrub-like, while Angiopteris and Mariattia may also rise to 2 ft. or more. But the tree-ferns proper are practically included within the family Cyatheaceae. This includes seven genera (Cyathea, Alsophila, Hemitelia, Dicksonia, Thysopteris, Cibotium and Balantium) and nearly 300 species, of which a few are herbaceous, but the majority arboreal and palm-like, reaching frequently a height of 50 ft. or more, Alsophila excelsa of Norfolk Island having sometimes measured 60 to 80 ft. The fronds are rarely simple or simply pinnate, but usually tripinnate or decompound, and may attain a length of 20 ft., thus forming a splendid crown of foliage. The stem may occasionally branch into many crowns.
The genera are of wide geographical range, mostly within the tropics; but South Africa, New Zealand, and the southern Pacific islands all possess their tree-ferns. In Tasmania Alsophila australis has been found up to the snow-level, and in the humid and mountainous regions of the tropics tree-ferns are also found to range up to a considerable altitude. The fronds may either contribute to the apparent thickness of the stem by leaving more or less of their bases, which become hardened and persistent, or they may be articulated to the stem and fell off, leaving characteristic scars in spiral series upon the stem. The stem is frequently much increased in apparent thickness by the downgrowth of aerial roots, forming a black coating several inches or even a foot in thickness, but its essential structure differs little in principle from that familiar in the rhizome of the common bracken (Pteris). To the ring or rather netted cylinder of fibrovascular bundles characteristic of all fernstems scattered internal as well as external bundles arising from these are superadded and in a tree-fern the outer bundles give off branches to the descending roots from the region where they pass into the leaves.
Tree-ferns are cultivated for their beauty alone; a few, however, are of some economic application, chiefly as sources of starch. Thus the beautiful Alsophila excelsa of Norfolk Island is said to be threatened with extinction for the sake of its sago-like pith, which is greedily eaten by hogs; Cyathea medullaris also furnishes a kind of sago to the natives of New Zealand, Queensland and the Pacific islands. A Javanese species of Dicksonia (D. chrysotricha) furnishes silky hairs, which have been imported as a styptic, and the long silky or rather woolly hairs, so abundant on the stem and frond-leaves in the various species of Cibotium have not only been put to a similar use, but in the Sandwich Islands furnish wool for stuffing mattresses and cushions, which was formerly an article of export. The “Tartarian lamb”, or Agnus scythicus of old travellers' tales in China and Tartary, is simply the wooly stock of Cibotium Barometz, which, when dried and inverted, with all save four of its frond-stalks cut away, has a droll resemblance to a toy sheep.
TREE FROG. Many different groups of tailless Batrachians (see Frog) are adapted to arboreal life, which is indicated by expansions of the tips of the fingers and toes, adhesive disks which assist the animal in climbing on vertical smooth surfaces. These disks do not act as suckers, but adhere by rapid and intense pressure of the distal phalanx and special muscles upon the lower surface, which is also provided with numerous glands producing a viscous secretion.
The best-known tree frog is the little Hyla arborea of continental Europe, rainette of the French, Laubfrosch of the Germans, often kept in glass cylinders provided with a ladder, which the frog is supposed to ascend or descend in prevision of the weather. But recent experiments conducted on scientific principles show that not much reliance can be placed on its prophecies. This frog is one of the smallest of European Batrachians, rarely reaching 2 in. in length; its upper parts are smooth and shiny, normally of a bright grass-green, which may change rapidly to yellow, brown, olive or black; some specimens, deprived of the yellow pigment which contributes to form the green colour, are sky-blue or turquoise blue; the lower parts are granulate and white.
The family Hylidae, of which the European tree frog is the type, is closely related to the Bufonidae or true roads, being distinguished from them by the presence of teeth in the upper jaw and by the claw-like shape of the terminal phalanx of the digits. It is a large family, represented by about three hundred species, two hundred and fifty of which belong to the genus Hyla, distributed over Europe, temperate Asia, North Africa, North and South America, Papua and Australia. Close allies of Hyla are the Nototrema of Central and South America, in which the female develops a dorsal broad pouch in which the young undergo part or the whole of their metamorphoses. The genus Phyllomedusa, also from Central and South America, are quadrumanous; the inner finger and the toe being opposable to the others, and the foot being very similar to the hand. These frogs deposit their spawn between the leaves of branches overhanging water, into which the tadpoles drop and spend their larval life.
TREE KANGAROO, any individual of the diprotodont marsupial genus Dendrolagus (see Marsupialia). Three species are inhabitants of New Guinea and the fourth is found in North Queensland. They differ greatly from all other members of the family (Macropodidae), being chiefly arboreal in their habits, and feeding on bark, leaves and fruit. Their hinder limbs are shorter than in the true kangaroos, and their fore limbs are longer and more robust, and have very strong curved and pointed claws. The best-known species, Lumholtz' tree kangaroo (Dendrolagus lumholtzi), is found in North Queensland. It was named by Professor Collett in honour of its discoverer, who described it as living on the highest parts of the mountains, in the densest scrub and most inaccessible places. It is hunted by the blacks with trained dingoes; the flesh is much prized by the blacks, but the presence of a worm between the muscles and the skin renders it less inviting to Europeans.
TREE-SHREW, any of the arboreal insectivorous mammals of the genus Tupaia. There are about a dozen species, widely distributed over the east. There is a general resemblance to squirrels. The species differ chiefly in the size and in colour and length of the fur. Nearly all have long bushy tails. Their food consists of insects and fruit, which they usually seek for in the trees. When feeding they often sit on their haunches, holding the food, after the manner of squirrels, between their fore paws. The pen-tailed tree-shrew (Ptilocercus lowi), from Borneo, Sumatra and the Malay Peninsula, is the second generic representative of the family Tupaiidae. The head and body, clothed in blackish-brown fur, are about 6 in. long; the tail, still longer, is black, scaled and sparsely haired for the upper two-thirds, while the lower third is fringed on each side with long hairs, mostly white. One shrew from Borneo and a second from the Philippines have been referred to a separate genus under the name Urogale everetti and U. cylindrura, on account of their uniformly short-haired, in place of varied, tails. (See Insectivora.)
TREE-WORSHIP. Primitive man, observing the growth and death of trees, the elasticity of their branches, the sensitiveness and the annual decay and revival of their foliage, anticipated in his own way the tendency of modern science to lessen the gulf between the animal and the vegetable world. When sober Greek philosophers (Aristotle, Plutarch) thought that trees had perceptions, passions and reason, less profound thinkers may be excused for ascribing to them human conceptions and supernatural powers, and for entertaining beliefs which were entirely rational and logical from primitive points of view. These beliefs were
