(From canna, a reed). A canal. It is also a round hollow instrument for embracing and holding a broken limb. Hippocrates speaks of its use, and Scultetus represents different sorts in his Armamentarium, part. i. tab. 23. According to Gorraeus, canalis signifies the hollow in the spine, which contains the medulla.

Canales semicirculares. The semicircular canals of the ear.

They are three in number, one superior and perpendicular, one posterior and perpendicular, and one horizontal; their size is nearly the same, but generally the superior perpendicular is the largest. They begin in the vestibulum, wind round the bone, and terminate in the vestibulum again: each at its origin has a separate orifice, but the two perpendiculars meet and return into the vestibulum by one common orifice. That these ducts contribute to hearing, appears from their being found in birds and fishes, though the cochlea is not found in either.

Canalis semis, petros. The bony half canal. See Auditus.

Canalis venosus. The vein of the funis umbi-licalia proceeds from the placenta to the navel of the child, and thence to the vena porta, with which it communicates by its main trunk, where there is a canal, which goes to the vena cava hepatica. It is called canalis, and ductus venosus; it runs between the lobulus Spigelii, and the left or small lobe of the liver. This duct enters the vena cava hepatica of the left side, just where it pierces the great trunk of the vena cava inferior.