The Flesh and Force-producers are most abundant in those plants which yield the substantive food of man. These plants belong principally to the group of cereal grasses, as wheat, oats, barley, &c., and leguminous plants, as peas, beans, lentils, &c. Of these the most important is wheat. At the western end of the gallery are shown samples of many cultivated varieties of wheat, oats, barley, rye, and maize, in the straw, and in grain. The Flesh and Force-producers exist also in large quantities in milk, and in the flesh of vertebrate animals, divided into mammals, birds, fishes, and reptiles. WHEAT. The wheat plant is grown all over the world, but flourishes mostly between the parallels of 25 and 60 degrees of latitude. It is more abundant in the northern than in the southern hemisphere. The varieties of wheat cultivated in Europe may be divided into those whose flowers produce awns, and those without these appendages, or _bearded_ and _beardless_ wheats. The fruits or seeds of these varieties are red or white, hence a further subdivision takes place into _red_ or _white_, bearded or beardless, wheats. Amongst the red bearded varieties is the fingered Egyptian or Mummy Wheat, which presents the peculiarity of several branches bearing fruits proceeding from its central stalk. Wheat is also called hard and soft according to its consistence, and winter and spring as it is sown at those seasons of the year. The red varieties yield the largest amount of grain, but the white the whitest flour. Wheat is preferred to the other cereal grasses as an article of food on account of its containing a larger quantity of flesh-forming matters. The flour also may be rendered very white by separating it from the husks, or bran, and the fruit is much more easily separated from the chaff than is the case with the other cereals. The proportion of flesh and force-producing to those of force-producers only, is more nearly adjusted to the requirements of the system in wheat than in any other food. Hence, probably, its very general use as an article of food amongst the populations of the hardest working nations in the world. In Case 26 is an analysis of the various constituents found in a pound of wheaten flour. The chemical analysis of barley, buckwheat, maize, millet, oats, rye, and rice may be inspected in the respective cases. BREAD.