The syrinx or lower larynx is the most interesting and absolutely avine modification, although absent as a voice-producing organ (probably due to retrogression) in most Ratitae, storks, turkey buzzards (Cathartes) and Steganopodes.
The syrinx is a modification of the lower part of the trachea and of the adjoining bronchi.
According to the position of the chief sound-producing membranes, three types of syrinx are distinguishable: - (i) Tracheo-bronchial, by far the commonest form, of which the two others are to a certain extent modifications.
(2) Syrinx bronchialis.
The Tracheophonae among the Passeriformes, the possessors of this specialized although low type of syrinx, form a tolerably well-marked group, entirely neotropical.
But indications of such a syrinx occur also in Pittidae, pigeons and gallinaceous birds (Gallidae), the last cases being clearly analogous.
Whilst the type of syrinx affords no help in classification, it is very different with its muscles.
There remains but one logical way, namely, to distinguish as follows: - (i) Passeres anisomyodi, in which the syrinx muscles are unequally inserted, either on the middle or on one end of the semi-rings, either dorsal or ventral.
(2) Passeres diacromyodi, in which some of the syrinx muscles are attached to the dorsal, and some to the ventral ends, those ends being, so to say, equally treated.
This way of using the characters of the syrinx for the classification of the Passeriformes seems simple, but it took a long time to accomplish.
- Syrinx muscles entirely lateral or attached to the dorsal or ventral corners of the bronchial semi-rings.
- Syrinx muscles of either side attached to the dorsal and ventral corners of the rings.
The sternum has no keel, and ossifies from lateral and paired centres only; the axes of the scapula and cora.coid have the same general direction; certain of the cranial bones have characters very unlike those possessed by the next order - the vomer, for example, being broad posteriorly and generally intervening between the basisphenoidal rostrum and the palatals and pterygoids; the barbs of the feathers are disconnected; there is no syrinx or inferior larynx; and the diaphragm is better developed than in other birds.'
SYRINX (Î£Ï…ÏÎ¹Î³Î¾), the Greek name for the pan-pipes.
The syrinx consisted of a varying number of reeds, having their open ends or embouchures in a horizontal line and their stopped ends, formed by the knots in the reed, gradually decreasing in length from left to right.
The syrinx or pan pipes owes its double name to ancient Greek tradition, ascribing its invention to Pan in connection with a well-known legend of the Arcadian water-nymph "Syrinx."
The syrinx was in use during the middle ages, and was known in France as frestel or fretiau, in medieval Latin as fistula panis, and in Germany as PansflÃ¶te or Hirtenpfeife (now PapagenoflÃ¶te).
The modern mouth-organ is the representative of the syrinx, although blown by means of a free reed.
A lover of music, he invented the shepherd's pipe, said to have been made from the reed into which the nymph Syrinx was transformed when fleeing from his embraces (Ovid, Metam.
From both birds and reptiles the class is distinguished, so far at any rate as existing forms are concerned, by the following features: the absence of a nucleus in the red corpuscles of the blood, which are nearly always circular in outline; the free suspension of the lungs in a thoracic cavity, separated from the abdominal cavity by a muscular partition, or diaphragm, which is the chief agent in inflating the lungs in respiration; the aorta, or main artery, forming but a single arch after leaving the heart, which curves over the left terminal division of the windpipe, or bronchus; the presence of more or fewer hairs on the skin and the absence of feathers; the greater development of the bridge, or commissure, connecting the two halves of the brain, which usually forms a complete corpus callosum, or displays an unusually large size of its anterior portion; the presence of a fully developed larynx at the upper end of the trachea or windpipe, accompanied by the absence of a syrinx, or expansion, near the lower end of the same; the circumstance that each half of the lower jaw (except perhaps at a very early stage of development) consists of a single piece articulating posteriorly with the squamosal element of the skull without the intervention of a separate quadrate bone; the absence of prefrontal bones in the skull; the presence of a pair of lateral knobs, or condyles (in place of a single median one), on the occipital aspect of the skull for articulation with the first vertebra; and, lastly, the very obvious character of the female being provided with milk-glands, by the secretion of which the young (produced, except in the very lowest group, alive and not by means of externally hatched eggs) are nourished for some time after birth.
(3) Syrinx trachealis.