separated again when the Dominion was formed in 1867. It played an active part in the Anglo-American War of 1812. It developed responsible government and English institutions. It rose in 1837, not against England, but against colonial grievances. It suffered from Fenian outrages in 1866. It prospered greatly during 1854-66. It has grown phenomenally since 1883. Its municipal governments closely approach civic perfection.

Ontario Agricultural College, Quelph, Can., was£stablished in 1874. Its experimental farm consists of 5 5 o acres. Dr. James Mills became president in 1879 and continued such until 1904. He was succeeded by George C. Creelman. The primary aim is to train young men for practical farming. There are special laboratories for chemistry, biology and physics. The library building cost $45,000. Sir William C. Macdonald of Montreal for instruction in home-science has erected buildings at a cost of $175,000 and presented them to the province. There are 23 teachers. The students each year average over 700. The college has graduated nearly 200 students, and sent many to teach in other colleges. It is admittedly one of the best equipped and most successful colleges of the kind in the world. As regards advanced examinations it is affiliated with the University of Toronto.

Ontario, Lake, one of the five Great Lakes of North America. It lies between Ontario and New York state, and has an elevation of 250 feet above the sea. It is the smallest of the group, covering 7,240 square miles and being 190 miles long and 55 wide. It forms the connection between Niagara River and the St. Lawrence. The level of its waters varies about three and a half feet at regular periods of from four to seven years, which, it is thought, may be due to an underground river. Welland Canal connects it with Lake Erie, Oswego Canal with Erie Canal and Hudson River, and Rideau Canal with Ottawa. It is subject to storms, the agitation of its waters by which may account for its seldom freezing, except along the shore.

O'nyx. See Marble.

Oogonium (ó'Ô-gō'nĭ-ŭm) (in plants), the female organ in thallophytes. It consists usually of a single cell, which produces a solitary egg, the oosphère. It may be a special cell set apart for this purpose from its beginning; or it may be an ordinary nutritive cell, which later becomes modified into an egg-producing cell. See Thallophytes.

Oosphère (ō'ŏ-s/ēr), the general name for the female cell or egg in plants. See Egg.

O'o'spore (in plants), the general name Eor the spore which results from the fertilisation of an egg by a sperm. The oospore s sometimes called a fertilized egg, and n plants which have a distinct alternation

of generations the oospore in germination always produces the sporophyte.

O'pal is a mineral, something like quartz, composed mainly of silica and water. It is never found in crystals, and is very easily broken. There are many kinds, so nearly resembling each other as to be with difficulty distinguished. The finest kind, known as precious, noble or oriental opal, is-partially transparent and of a bluish or yellowish white, with a beautiful play of brilliant colors produced by small fissures which refract the light. It is never cut in facets, as diamonds are, because its play of colors is better on 'a convex surface. It is used in jewelry. The finest opals are brought from Hungary. Opal is also found in Saxony and in South America. The common opal is white, yellow, green, red or brown, but without any play of colors. It is not at all rare, occurring in veins and holes in rocks.

Op'era is a drama which is sung, accompanied by a full orchestra or by a chorus of musical instruments. It makes use of the aria or song, duets, trios, the recitative or declamation, instrumental interludes or whatever the situation requires. The introduction or opening is called an overture. There are three chief classes or schools, the Italian, the German and the French. The Italian opera is the earliest, dating as early as iŏoo, and is noted for melody. Scarlatti (1659-1725) may be considered its founder. The most famous modern Italian composer is Rossini, his Barber of Seville and William Tell both retaining a place on the modern stage. Bellini, Donizetti, and Verdi are other well-known composers of this school.

The early opera in Germany was Italian, Dresden and Vienna being the centers. The national school was founded at Hamburg by Keyser, who wrote more than 100 operas (1694-1734). Mozart's first work was Italian in form, though surpassing the Italians in their own field ; but his Magic Flute was the first national romantic opera. Beethoven composed but one opera, Fidelio, while Weber used the national folklore in Der Freischütz (Free Archer) with great effect. Melodrama originated in Germany. The singer recites his part in a speaking voice, while the music of the orchestra seeks to give the meaning of the scene to the audience:

French grand opera was founded by Sully, a Florentine, and reformed by Glück, the German composer, while Cherubini, Rossini, Meyerbeer and Wagner were foreigners who aided in its development. The French school paid particular attention to rhetoric, and the use of the recitative or recitation has always been prominent. Italian opera became the fashion in London from the time of Hándel, and was introduced into America in 1825. See Memoirs of the Opera by Hogarth and Essays on Modern Opera by Edwards.