(from follis, a bag), a species of seed-vessel, first mentioned by Linnaeus in his Delineatio Plantarum. It generally consists of one valve, which opens from bottom to top on one side, and has no suture for fastening or attaching the seeds within it. FOLLICULI are likewise defined by the same author to be small glandular vessels distended with air, which appear on the surface of some plants, as at the foot of water-milfoil, and on the leaves of aldrovanda. In the former the leaves in question are roundish, and furnished with an appearance like two horns; in the latter, pot-shaped and semicircular.

FOLLIS anciently signified a little bag or purse, and hence it came to be used for a sum of money; nay, different sums were called by the same name. Thus the scholiast on the Basilics mentions a follis of copper which was worth but the twenty-fourth part of the milliarensis; the glossae nonicae, quoted by Gronovius and others, were, one of 125 milliarenses, and another of 250 denarii, which was the ancient sestertium; and three different sums of eight, four, and two pounds of gold were each called follis. According to the account of the scholiast, the ounce of silver, which contained five milliarenses of sixty to the pound, was worth 120 folles of copper. The glossographer, describing a follis of 250 denarii, says it was equal to 312 pounds six ounces of copper; and as the denarius of that age was the eighth part of an ounce, an ounce of silver must have been worth 120 ounces of copper; therefore the scholiast's follis was an ounce of copper, and equal to the glossographer's nummus. But as Constantine's copper money weighed a quarter of a Roman ounce, the scholiast's follis and the glossographer's nummus contained four of them, as the ancient nummus contained four asses.