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Rh under Alonzo de Ojeda, by whom he was entrusted with the charge of the unfortunate settlement at San Sebastian. He accompanied Balboa (whom he afterwards helped to bring to the block) in the discovery of the Pacific; and under Pedrarias d'Avila he received a repartimento, and became a cattle-farmer at Panama. Here in 1522 he entered into a partnership with a priest named Hernando de Luque, and a soldier named Diego de Almagro, for purposes of exploration and conquest towards the south. Pizarro, Almagro and Luque afterwards renewed their compact in a more solemn and explicit manner, agreeing to conquer and divide equally among themselves the opulent empire they hoped to reach. Explorations were then undertaken down the west coast of South America, in which Pizarro, though left for months with but thirteen followers on a small island without ship or stores, persisted till he had coasted as far as about 9° S. and obtained distinct accounts of the Peruvian Empire. The governor of Panama showing little disposition to encourage the adventurers, Pizarro resolved to apply to the sovereign in person for help, and with this object sailed from Panama for Spain in the spring of 1528, reaching Seville in early summer. Charles V. was won over, and on the 26th of July 1529 was executed at Toledo the famous capitulacion, by which Pizarro was upon certain conditions made governor and captain-general of the province of New Castile for the distance of 200 leagues along the newly discovered coast, and invested with all the authority and prerogatives of a viceroy, his associates being left in wholly secondary positions. One of the conditions of the grant was that within six months Pizarro should raise a sufficiently equipped force of two hundred and fifty men, of whom one hundred might be drawn from the colonies, as he could not make up his due complement he sailed clandestinely from San Lucar in January 1530. He was afterwards joined by his brother Hernando with the remaining vessels, and when the expedition left Panama in January of the following year it numbered three ships, one hundred and eighty men, and twenty-seven horses. The subsequent movements of Pizarro belong to the history of (q.v.). After the final effort of the Incas to recover Cuzco in 1536-37 had been defeated by Diego de Almagro, a dispute occurred between him and Pizarro respecting the limits of their jurisdiction. This led to battle, Almagro was defeated (1538) and executed; but his supporters conspired, and assassinated Pizarro on the 26th of June 1541.

 PIZZICATO (from Ital. pizzicare, to pluck or twitch), a term in music for a direction to the players of stringed instruments, that the passage so marked is to be played by plucking the strings with the fingers instead of using the bow.

 PIZZO, a seaport of Calabria, Italy in the proxince of Catanzaro, 72 m. by rail N.E. of Reggio, situated on a steep cliff overlooking the Gulf of Santa Eufemia, 351 ft. above sea-level. Pop. (1901), 9172. It has an old castle, in which Joachim Murat, ex-king of Naples, was shot on the 13th of October 1815. The people engage in tunny- and coral-fishing. In 1783 the town was almost destroyed by an earthquake, and it suffered some damage from the same cause in 1905.

 PLACARD (15th cent. Fr. plackart, from plaquier; mod. plaquer, to plaster), a bill or poster pasted or affixed to a wall or in anv prominent position for the purpose of giving notice to the public of a proclamation, police or other regulations, or of forthcoming events or the like.

 PLACE (through Fr. from Lat. plates, street, Gr. πλατύς, wide), a definite position in space, whether of limited or unlimited extent, situation or locality; also position in a series or rank; or an office, or employment, particularly one in the service of a government. Special applications are to an open space in a town, a group of buildings, row of houses, or as the name of a residence or manor-house. In certain cases this latter use accounts for the occurrence of parts of a town being known as Place, e.g. Ely Place in London, formerly the site of the town residence of the bishops of Ely. A " place of arms " (Fr. place d'armes), in fortification, means the wide spaces (suitable for the assembly of troops for a sortie) made by the salients and re-entrants of the covered Way. The phrase is also used in a strategic sense to express an entrenched camp or fortress in which a large army can be collected under cover previous to taking the field.

 PLACENTA (Lat. for a cake), in anatomy, the organ by which the embryo is nourished within the womb of its mother. When the young one is born the placenta and membranes come away as the "afterbirth." In human anatomy the organ is a circular disk about seven or eight inches in diameter and one and a quarter inches in thickness at its centre, while at its margin it is very thin and is continuous with the foetal membranes. It weighs about a pound.

In order to explain the formation of the placenta it is necessary to encroach to some extent on the domain of physiology. Before each menstrual period, during the child-bearing age of a woman, the mucous membrane of the uterus hypertrophies, and, at the period, is cast off and renewed, but if a fertilized ovum reaches the uterus the casting off is postponed until the birth of the child. From the fact that the thickened mucous membrane lining the interior of the uterus is cast off sooner or later, it is spoken of as the "decidua." The fertilized ovum, on reaching the uterus, sinks into and embeds itself in the already prepared decidua, and, as it enlarges, there is one part of the decidua lying between it and the uterine wall ("decidua serrotina" or "basalis") one art stretched over the Surface of the enlarging ovum ("decidua regexa" or "capsularis") and one part lining the rest of the uterus ("decidua vera") (see fig 1.).

From A. H. Young and A. Robinson, in Cunningham's Text-Book of Anatomy.

1.—Diagram representing a very young human ovum almost immediately after its entrance into the decidua, and whilst the place of its entrance is still covered with a plug of fibrin. The ectoderm has already proliferated and embraced spaces which contain maternal blood and are continuous with the maternal blood-vessels.

It is the decidua basalis which is specially interesting in considering the formation of the placenta. That part which is nearest the ovum is called the "stratum compactum" but farther away the uterine glands dilate and give a spongy appearance to the mucous membrane which earns this particular layer the name of "stratum spongiosum." Processes grow out from the surface of the ovum which penetrate the stratum compactum of the decidua basalis and capsularis and push their way into the enlarged maternal blood sinuses; these are the "chorionic villi." Later, the "allantoic" or "abdominal stalk" grows from the mesoderm of the hind end of the embryo into the chorionic villi which enter the decidua basalis, and in this blood vessels pass which push their way into the maternal blood sinuses. Eventually the original walls of these sinuses, together with the false amnion, disappear, and nothing now separates the maternal from the foetal blood except the delicate walls of the foetal vessels covered by some nucleated noncellular tissue, known as synctium, derived from the chorionic epithelium, so that the embryo is able to take its supply of oxygen and materials for growth from the blood of its mother and to give up carbonic acid and excretory matters. It is the gradual enlargement of the chorionic villi in the decidua basalis together with the intervillous maternal blood sinuses that forms the placenta; the decidua capsularis and vera eventually become pressed