(Gr. soma). A single segment in the body of an Articulate animal.
The organ in which spermatozoa are produced.
(Gr. sperma, seed; and zoon, animal). The microscopic filaments which form the essential generative element of the male.
(Gr. sphairidion, a little ball or sphere). Minute stalked appendages with button-shaped heads carried by most living Sea-urchins, and supposed to be organs of sense.
(Lat. spiculum, a point). Pointed needle-shaped bodies.
The organs by means of which Spiders and Caterpillars spin threads.
(Lat. spiro, I breathe). The breathing-pores, or apertures of the breathing-tubes (tracheae) of Insects. Also the single nostril of the Hag-fishes, the "blow-hole " of Cetaceans, etc.
(Gr. splagchna, viscera ; skeletos, dry). The hard structures occasionally developed in connection with the internal organs or viscera.
(Gr. spoggos, a sponge). The division of Protozoa commonly known as sponges.
(Gr. spora, seed). Germs, usually of plants ; in a restricted sense, the reproductive "gemmules" of certain sponges.
(Gr. statos, stationary ; blastos, bud). Certain reproductive buds developed in the interior of Polyzoa, but not liberated until the death of the parent organism.
(Gr. steganos, covered ; and ophthalmos, the eye). Applied by Edward Forbes to certain Medusae, in which the sense-organs ("marginal bodies") are protected by a sort of hood. The Steganophthalmata are now separated from the true Medusidae, and placed in a separate division under the name Lucernarida.
(Lat. stella, star). Sometimes employed to designate the order of the Star-fishes.
(Gr. sternon). The breast-bone.
The breathing-pores in Insects and Arachnida.
(Gr. stolos, a sending forth). Offshoots. - The connecting processes of sarcode in Foraminifera; the connecting tube in the social Ascidians ; the processes sent out by the coenosarc of certain Actinozoa.