This is a disputed question. Some authorities are of the opinion that the liquid collected by bees from the nectaries of flowers does not differ materially from honey, and that accordingly it is correct to say that bees gather honey rather than make it. Others insist that the nectar undergoes considerable elaboration in the honey stomach or sac of the bee before it is deposited in the wax cells in the form of the sweet viscid liquid which we call honey, and that therefore it is more accurate to say that bees gather nectar and make honey. To what extent the nectar is altered in the crop of the bee is difficult to determine because there are so many different kinds of nectar and honey. The chemical composition of both varies widely. Nevertheless nectar is the raw material used by bees in manufacturing honey. The U. S. Department of Agriculture officially defines honey as "the nectar and saccharine exudations of plants, gathered, modified, and stored in the combs by honeybees". Under this definition nectar in its original state is not honey, although in popular parlance it is so regarded. It is erroneous to suppose, as some people do, that honey is nectar which has been partly digested by bees. Honey is not a product of digestion in the accepted sense of the term. Bees have two stomachs, or more accurately speaking, they have a stomach and a honey sac. The first performs the ordinary processes of digestion, while the second merely receives and retains for a time the nectar, which may or may not be essentially modified and which is regurgitated and deposited in the honey-cells.