[a. F. vacuole (Dujardin), f. L. vacu-us empty.]
1. A small cavity or vesicle in organic tissue or protoplasm, freq. containing some fluid.
a. Zool. and Anat. 1853. Ray Soc. Bot. & Physiol. Mem., 534. All these properties had already been observed by Dujardin;… the aqueous spaces or hollows he named ‘Vacuoles,’ regarding them as the most characteristic feature of the substance.
1859. Huxley, Oceanic Hydrozoa, 10. The structure of the villi and vacuoles in Athorybia.
1897. Allbutt’s Syst. Med., II. 224. Into the vacuoles or loculi of this net-work the serum exudes.
b. Bot. 1875. Darwin, Insectiv. Plants, xv. 351. Two or three vacuoles or small spheres appeared within some of the larger globules.
1885. Goodale, Physiol. Bot. (1892), 280. In numerous succulents the vacuoles of the assimilating cells frequently contain a thin mucus.
attrib. 1882. Vines, trans. Sachs’ Bot., 585. The centre of the sac is filled in the unripe seed with a clear vacuole-fluid.
2. An empty or open space (in a comet).
1881. Science, II. 317. In this envelope was a curious oval vacuole, behind the nucleus, but on the preceding side of the axis of the tail.
