COROSOS, or IVORY-NUTS, are produced by Phytelephas macrocarpa, growing in central America and Columbia, (Humboldt.) They are described as seeds with osseous albumen; the tree is a genus allied to the Pandaneae, or Screw Pines, and also to the Palms. The nuts are of irregular shapes, from one to two inches diameter, and when enclosed in their thin husks, they resemble small potatoes covered with light brown earth; the coat of the nut itself is of a darker brown, with a few loose filaments folded upon it. The internal substance of the ivory-nut resembles white wax rather than ivory; it has, when dried, a faint and somewhat transparent tint, between yellow and blue, but when opened it is often almost grey from the quantity of moisture it contains, and in losing which it contracts considerably. Each nut has a hole, which leads into a small, central, angular cavity; this, joined to the irregularity of the external form, limits the purposes to which they are applied - principally the knobs of walking-sticks, and a few other small works.

Fig. 28 is the section of the ivory-nut at right angles to the stalk, and half size; and fig. 29 is the section through the stalk itself, which proceeds from s.