Sieve

(sir). A ve el with a rciicu lated bottom, used for the separation of puly i from coarse substances. The gauge of the sieve 1 usually expre ed in the number of meshes per square inch. S. -cells, long cells of tubular or prismatic form constituting an e ential element in fibro-vascular bundles of the inner bark of exogenous stems. They are peculiar in the po e ion of circumscribed panels, with tine perforations, which allow of communication between contiguous cells. S.-disc. See S. -plate. S.hypha; a hypha in which sieve-plates occur. S.plates, the perforated panels of sieve-cells occurring at the points of contact of sieve-cells. S. -pores, the perforations in the panels of sieve-cells. S. -ti ue, a cellular ti ue made up of thin-walled cells which po e areas with sieve-like markings. The ti ue is characteristic of the phloem. S. -tubes. See S.-cells. S. -ve el. See S.-cells.