Sap

the circulating fluid of plants. Sap is to the plant what blood is to the animal. It courses through passages corresponding to the veins and arteries of an animal. It is like blood in that it consists largely of water, carrying nutritive particles from the ground to the parts of the plant where they are needed. It also circulates through the leaves and other breathing portions of the plants, presenting itself to the influence of the sunlight and of air. Plant life is as dependent upon sap as animal life is dependent upon blood. The analogy between sap and blood may be carried still farther. In addition to blood, the body of an animal may contain other liquids, as saliva and lymph; so, in addition to sap, many plants have special ducts containing liquids other than sap. Turpentine, for instance, is made, not from the sap, but from the contents of the turpentine ducts of the southern pine. Many economic uses are made of sap. The juices of fruits are hoards of concentrated sap; we have sugar and sirups from the sap of the maple and the sugarcane; rubber from the sap of the rubber tree; opium from the sap of the poppy plant; and pulque from the sap of the agave plant. Many gums are the dried sap of corresponding shrubs and trees. See Turpentine; Maple; Rubber