Vascular.—Full of vessels. In this instance, full of capillary blood-vessels.
908. Why have we nails at our fingers' ends?
Because they give firmness to the touch, and enable us to apply the extremities of the fingers to many useful purposes for which they would otherwise be unfitted. They enable us to press the tips of the fingers, where the highest degree of sensitiveness prevails, so as to bring the largest amount of nervous perception into the sense of touch.
909. Why do white spots occur upon the nails?
Because the vascular surface underneath is attached to the horny texture of the nail; but by knocks and other causes, the nail sometimes separates in small patches from the membrane below, and becomes dry and opaque.
910. Why is there a circular line of whitish colour at the root of the nail?
Because there the nail is newly formed by the vascular substance out of which it grows, and has not yet assumed its proper horny and transparent nature.
911. Why is the eyeball white?
Because the blood-vessels that supply its surface are so very fine that they do not admit the red corpuscles of the blood.