Sinus (Lat. sinus, a curve, fold, or hollow), a hollow excavation, recess, or pocket in any structure.

Smegma (Gr. smegma, a cleansing substance), the fatty substance secreted by the sebaceous glands of the prepuce.

Spasmodic (Gr. spasmodes), having the nature of a convulsion or spasm.

Spavin, a disease of bones in which an enlargement appears on the inner and lower part of the hock joint.

Specific (Lat. species, species; facere, to make), that which distinguishes a thing, or makes it of the species of which it is.

Specific gravity, the measured weight of a substance compared with that of an equal volume of another taken as a standard.

Spermatic (Gr. spermeitikos - sperma, seed), relating to the semen.

Spermatozoa (Gr. sperma, semen; zoon, animal), the essential elements of fecundation.

Sphenoid (Gr. sphen, wedge, and eidos, likeness), wedge-shaped, relating to the sphenoid bone, an important bone of the skull.

Sphincter (Gr. sphingkter, sphingein, to squeeze), a muscle surrounding and enclosing an orifice such as the anus.

Spirillum (Lat. spirillum, a curl), a bacterium whose elements are curved, often forming a spiral of several turns.

Splint, applied to a bony excrescence on the canon bone of the horse.

Sporadic (Gr. sporadikos, scattered), applied to diseases which may spread, but which are not epidemic, and occur here and there.

Sporozoa (Gr. spora, seed, and zoon, an animal), a class of parasitic protozoa.

Squamous (Lat. squamosus, scaly, squama, a scale), a skin disease in which a scaly condition exists.

Staphyline (Gr. staphyle, the uvula), pertaining to the uvula or the palate.

Staphylococcus (Gr. staphyle, bunch of grapes, and kokkos, berry), a micrococcus of which for the most part the individual cocci in a culture are solitary.

Staphyloma (Gr. staphyle, bunch of grapes), a giving way or bulging of the cornea.

Steapsin (Gr. stear, fat), a ferment which resolves fats into glycerine and their corresponding fatty acids.

Stearin (Gr. stear, fat), a substance contained in fat and composed of stearic acid and glycerine.

Sterility (Lat. sterilis, barren), the condition of an animal or plant when it is incapable of reproducing itself.

Sterilize (Lat. sterilis, barren), to render sterile or barren; to destroy the vitality of germs and prevent their reproduction.

Stertorous (Lat. stertere, to snore), breathing with a snoring sound.

Stethoscope (Gr. stethos. breast; skopein, to examine), an instrument through which the organs of breathing, and the heart and arteries, are examined as to their sounds.

Stomatitis (Gr. stoma, mouth; itis, inflammation), inflammation of the mouth.

Strangles (Gr. stranyale, a halter), an infectious disease of the air passages, especially of the nasal cavities, of the horse, ass, and mule, associated with a suppurative condition of the submaxillary and other glands.

Streptococcus (Gr. streptos, twisted; kokkos, a berry), a genus of microbes in which the cocci are arranged in strings or chaplets.

Streptothrix (Gr. streptos, twisted; thrix, the hair), an order of fungi the cells of which unite into simple or branching threads.

Stricture (Lat. strictura, stringere, to compress), an abnormal contraction of a duct or passage from external pressure, or as a result of inflammation or other changes.

Strumous (Lat. strumosus, struma, scrofula), having the nature of scrofula.

Styloid (Gr. stylos, pillar), resembling a slender cylindrical column.

Subcarpal (Lat. sub, under; Gr. karpos, the wrist), situated under the carpus or wrist: the wrist of the horse is spoken of as the knee.

Sublobular (Lat. sub, under; lobulus, a lobule), situated beneath a lobule.

Submaxillary (Lat. sub, under; maxilla, jaw-bone), lying beneath the lower maxilla or jaw-bone.

Sudoriparous (Lat. sudor, sweat; parere, to beget), producing or secreting sweat.

Suffrago (Lat. suffrago, hock), the hock; os suffra-ginis, the bone of the hock.

Supplemental (Lat. supplementum), applied to the air that can still be exhaled after ordinary expiration.

Suspensory (Lat. sub, under; pendere, to hang), a structure by which another part hangs.

Symbiosis (Gr. syn, along with, and bios, life), the intimate association of living organisms, one of which is necessary to the other.

Symbiotes (Gr. syn, with, bios, life), a small parasite infesting the legs of horses.

Sympathetic (Gr.sympathetikos, sympathetic), effecting sympathy or consentaneous activity.

Symphysis (Gr. syn, together, and phyein, to grow), a growing together, a union; especially, line of union of the two pubic bones, symphysis pubis.

Synarthrosis (Gr. syn, together, and arthron, joint), a form of joint in which the bones are immovably united together.

Syncope (Gr. synkope, a cutting short), a swooning or fainting, a temporary suspension of the functions of respiration and circulation.

Synovial (Gr. syn, together, and Lat. ovum, egg), relating to the synovia, which is a lubricating liquid connected with a joint.

Synthesis (Gr. synthesis - syn, with; tithenai, to place), in chemistry, the formation artificially of a compound by combining its component elements.

Systole (Gr. systole, contraction), the contraction of the heart and arteries, by which the blood is propelled along the vessels.

T

Taenia (Gr. tainia, a band), a flat parasite composed of a number of flat segments: a tape-worm.

Taenia echinococcus (Gr. tainia, a band; echinos, a hedgehog; kokkos, a berry), a tape-worm in. in length.

Taenia perfoliata (Gr. tainia, a band; Lat. per. through; folium, a leaf), a tape-worm composed of consecutive segments, increasing in size posteriorly, measuring 2 in. long and 3/8 in. wide.

Taenia plicata (Gr. tainia, a band ; Lat. plicare, to fold), a tape-worm about 3 in. long and | in. wide.