Page:The New International Encyclopædia 1st ed. v. 18.djvu/515

* SPHINX. 443 SPIDER. Sphinx was considered to represent Harmachis (ij.v.), a .spec-ial form of the sun-{;od, and its office was to serve as a yiiardian of the necropolis near the pyramids. It has been supposed lo be the worl< of King Chephren of the Fourtli Dynasty, and some archicologists liave even assigned it to an earlier period, but the existing evidence is insullicient to fix its date with any degree of accuracy. Consult: Vyse, The Pyramids of Gizeh, (London, 1840) : Lepsius, Dtnlcnuilcr (Berlin, 1849-58) : Pcrrot and Chipiez, llislory of Art in Ancioit E<i!ijit (London, 1883) ; Baedeker, jleji/p- ien (4th ed., Berlin, 1897) ; Petrie, A History of Egypt (New York, 1899) ; Budge, A History of Egypt (ib., 1902). See Plate of Pyk-^hids. SPHINX MOTHS. IMoths of the family Sphingid;e. dc-eriliLil under ILvwK-MOTH. Promi- nent American examples are depicted on the Col- ored Plates of JIoTHS, and of Insects. SPHYGMOGKAPH (from Gk.<T(Si';/idf,si)/ii/(/- mos, pulse + -pi:oiip, graphein, to write). An instrument invented by ^■ierovdt and perfected by Marey, by which are ascertained and perma- nently recorded the force and frequency of the pulse-beat and the changes which it undergoes. It consists of two essential parts: (1) Of two levers, one of which is so delicately adjusted on the vessel the pulsation of which it is desired to examine, that on each expansion of the vessel the lever undergoes a corresponding slight eleva- tion; this lever communicates by a perpendicular arm with a second, to which it transmits the impulse recei'ed from the vessel; the extremity of this second lever is armed with a pen-point, which records the movement thus indicated on a movable plate, controlled by the second part of the instrument. (2) The second portion consists <if a plate, moved by clockwork, and bearing a strip of paper on which the sphygmogram is written. The instrument may be condjined with a microphone, constituting a sphygmophone. The pulsations may be seen by an appliance termed a sphygmoscope. SPICCATO, spe-ka'to (It. separated). A term in music indicating a distinct and detached mode of performance. Its usual application is to music for bowed instruments, where it im- plies that each note is to be pla.ved with a springing bow. The bow is allowed lo fall b.v its own weight upon the string; it rebounds and falls again, tlius producing the next tone. SPICE BUSH. See Fever Bush. SPICE ISLANDS. A group of islands in the Dutch East Indies. See Moluccas. SPICES. See Flavokixg Plants. SPIDER (ME. spither, from AS., Goth., OHG. spiiiiiuii. (jer. spinnen, to spin; cf. OHG. spinna, Ger. 8pinne, spinner, spider). Any mendjer of the Araneida, an order in the class Arachnida. The arachnids are distinguished from insects by the possession of four pairs of legs ; while spiders are separated from other Arachnida by the presence of spinning-organs near the tip of the body. The body of a spider is divided into two portions connected b,v a small slender pedi- cel. The anterior part is called 'cephnlothorax.' and is supposed to represent the combined head and thorax of insects. The posterior part is the 'abdomen.' On the anterior part of the cephalothorax are the eyes, common!}' eight in Vol. X VIII.— 29. number, and frequently arranged in two trans- verse rows of four each. In the lower front margin of the cephalothorax are the mouth- parts. These consist of a pair of jaws, some- times called mandibles or "falces;' a pair of palpi, whose basal joints are enlarged into max- ilhe: and a median unpaired lower lip. The mandibles are two-jointed; the basal joint is very large and stout, the apical one is .small, claw-like, and called the 'fang.' The [lalpi are iiliform, and six-jointed. In the female they are simple and often terminate in a claw; in the male, however, the apical joint is curiously modified into a complicated accessory sexual organ, suited to carry and appl.v the seminal fluid. The four pairs of legs are similar in structure, but variable in length. Each con- sists of seven joints, and ends in two or three toothed claws. The spiders that live on webs usualh' have three claws, the median more curved than the others; while other spiders com- monly have but two. In place of the median claw is sometimes a dense fascicle of hairs. The abdomen of spiders is generall.v soft, tumid, and has no apparent joints. The genital organ opens near the base of the abdomen beneath. The male aperture is inconspicuous, but the female vulva or epigynum is often very prominent, and some- times quite complicated. At the apex of the abdomen are four to six short, often two-jointed pieces, the spinnerets or spinning-organs. Each spinneret has on its surface many minute ori- fices, from each of which ma.v issue a thread, and the many threads joined together make the spider's line. The substance which exudes from the spinnerets is glutinous, but dries on contact with the air. Some spiders possess an accessory spinning-organ, a transverse surface in front of the base of the spinnerets known as the 'cribel- lum.' Correlated «ith this is a ro:- of curved hairs on the hind metatarsus, called the 'calamis- trum.' The spider draws the row of hairs over the cribellum and combs out a curled or tangled thread of silk. The mouth of the spider opens into a short oesophagus, which leads to a sucking-stomach which draws up the liquid food. From the posterior part of this organ arise two branches which extend upward and forward and meet over the mouth : each lirancli gives oft' on the outer side four smaller branches, one in front of each leg, and these unite below the sucking-stomach. From the stomach arises the intestine. Avhich passes into the abdomen and opens just behind the spinnerets. In the abdomen just above the intestine is a long tubular heart or pulsating vessel, with openings in front, behind, and along the sides. The nervous system is represented liy a large, long ganglionic mass lying on the floor of the cephalothorax. In front is a smaller mass which gives rise to nerves to the eyes and jaws. At the base of the abdomen below there is a cavity on each side, nearly filled by a series of thin plates through which the air reaches the blood. These are the 'lungs.' Spiders also have a pair of branching trachea;, which open just in front of the spinnerets. The silk-glands lie above the spinnerets and along the floor of the abdomen. The,Y are of two kinds, most of them short, but two are larger and very long. Each silk-gland has a separate opening or duct in the spinnerets.