Circle

(sir'-kl). A ring; a line, even point of which is equi-distant from a point called the center. C. of Diffusion. 1 The plexus of ve els formed by the short ciliary arteries upon the sclerotic, at the entrance of the optic nerve. 2. The circulus venosus mammae. See also, Circulus. C. of Will is, the remarkable arterial an as to•mos is at the base of the brain. The pa age between the anterior cerebral arteries anteriorly, and the internal carotids and middle and posterior cerebral arteries posteriorly, by communicating ve els.