=Sceptre=, _n._ L. _sceptrum_, a staff to lean on; a sceptre; a staff of office; the staff of kingship. =Secrete=, _v._ L. _secernere_, to separate; to form from the materials of the sap or the blood a new substance. The organ that secretes is called a gland. =Secundus=, _n._ L. _secundus_, second; the name given in this book to a suppositional plant. =Seed=, _n._ The fertilized and matured ovule of a flower. =Seed-coat=, _n._ The outer covering to a seed. =Seedlet=, _n._ A little seed. =Sepal=, _n._ L. _separ_, separate; one of the separate leaves that form the calyx. =Septimus=, _n._ L. _septimus_, seventh; the name given in this book to a suppositional plant. =Sextus=, _n._ L. _sextus_, sixth; a name given in this book to a suppositional plant. =Shrub=, _n._ A woody, branching plant, smaller than a tree. =Silica=, _n._ L. _silex_, flint; a substance found very abundantly in the earth’s crust. It is very hard, and when melted forms glass; it is found in solution in some springs and is taken up by certain plants and deposited on or near the surface. =Skin=, _n._ The outside covering of an animal or plant. =Skin cells=, _n._ The cells of which the skin is made up. =Snowdrop=, _n._ An early spring flower cultivated in gardens; it sometimes blossoms under the snow. =Soda=, _n._ A compound of sodium, carbon, and oxygen; found in the composition of some plants. =Sodium=, _n._ One of the elements of common salt, and also found in the tissues of plants and animals. =Sorrel=, _n._ A.-S. _sūr_, sour; a kind of plant with acid leaves. =Sphinx=, _n._ In Greek mythology, a monster with the head of a woman, the wings of an eagle, and the claws of a lion; she sat on a rock and proposed a riddle to all who passed and killed those who could not guess it. The Egyptian sphinx has no wings and is not the same as the Greek monster; it is generally placed in rows in avenues leading to temples, and the largest and most famous Egyptian sphinx is the Great Sphinx near the great pyramids of Ghizeh; it held a temple between its paws. =Spring beauties=, _n._ Pretty, delicate, and early spring flowers. =Spur=, _n._ A pointed instrument worn on the heel to goad a horse; any sharp projection formed like a horseman’s spur. =Stamen=, _n._ L. _stamen_, thread, string, fibre; the floral organ containing the fertilizing pollen. The stamen, like the pistil, is believed to be a modified leaf. =Starch=, _n._ A substance composed of carbon, hydrogen, and oxygen, forming one of the principal elements in plants and necessary as food to animals. =Stiffening cells=, _n._ The woody cells and other tough-walled cells that serve to keep the shape of a plant. =Stigma=, _n._ The structure at the top of the style where the pollen is received.