The most valuable forms of vegetable foods are those obtained from the seeds of certain kindred plants {Graminacece) - wheat, rye, maize, oats, rice, etc.; which when ground are used either as "whole meal," or, the integument ("bran") being removed, as flour. They contain different kinds of proteid. (1) A native albumin soluble in water and coagulable by heat, and in many respects like animal albumin; but, as it cannot be obtained pure, it is imperfectly known. (2) Vegetable fibrin, an elastic body, which coagulates spontaneously and is difficult to separate. (3) Vegetable glue or gliadin, which gives the peculiar adhesiveness to the gluten, as the proteid mixture obtainable from corn is commonly called. Cereals also contain traces of fat, and a very large proportion of starch and some salts.