MONCECISM. 731 MONONGAHELA. small gametopliyto (prollialliuni) bearing both antheridium and archegoiiiuni. With the intro- duction of hctcrospory (q.v. ). however, the sexual plants are absolutely dill'erentiated, one individual lieing male and another female. Since all the Hcnvering plants are heterosporous, it follows that they are essentially not nioineeious in the sense of the term as used among mosses and ferns. In the applieation of the term to stamens and pistil-s, however, rather than to se.K organs, the majority of (towering plants are found to 1)6 "moniecious" ; that is, with the sta- mens and pistils not only upon the same plant, but in the same flower. MONOGRAM (Lat. monogram ma, from Gk. fuipoypdiMiiaToi, monofjraminatos, consisting of a single letter, from Gk. fjJ>voi,monos, single -(- 7po^^ im., gramma, letter, from ypa<p(i.v, graphcin, to write). A character composed of two or more let- ters of the alphaljet, often interlaced with other lines, and used as a ciplier or abbreviation of a name. A perfect monogram is one in which all the letters of the word are to be traced. The use of monograms began at a very early date. They are found on Greek coins, medals, and seals, and are particularly numerous on the coins of Mace- donia and Sicily. Both on coins and in MSS. it was the practice to present the names of States and cities by monograms, of w'hich above 500 are known, but some have not been de- ciphered. Jlonograms occur on the family coins of Rome, but not on the coins of the earlier Roman emperors. Constantinc placed on his coins
- & one of the earliest of Christian monograms
which is to be traced in the recesses of the catacombs, cooiiposed of the first and second let- ters of XPiffTos (Christus) , a monogram which also appeared on the Labarum (q.v.), and was con- tinued on the coins of the succeeding emperors of the East down to Alexander Comnenus and Theodorus Lascaris. We often find it combined with the first and last letters of the Greek al- phabet (Rev. i. 8). Another well-known mono- gram is that of the name of .Jesus, IH.S, from the first three letters of IHSoCf, though some- times explained as standing for the three Latin words lesus Hominum Halrator (Jesus, Saviour of Men) . Popes, emperors, and kings of France during the Middle Ages were in the practice of using a monogram instead of signing their names. Al- most all the coins of the French kings of the ■Carlovingian race bear their respective mono- grams, as also do those of Alfred and some of the other Saxon kings of England. Painters and engravers in Germany and Italy liave used monograms to a large extent as a means of distinguishing their works. In these, the initial letters of their names were often interwoven with figures of a symbolical char- acter, so as to form a rebus on the artist's name. The first typographers distinguished their pub- lications by wood-cut vignettes, whose inven- tion is ascribed to the elder Aldus; but besides these, each made use of a monogram or cipher, a series of which, well known to the bibliographer, fixes the identity of the ancient editions, Ger- man, Italian, and English, from the invention of printing down to the middle or end of the sixteenth century. For a detailed accoiuit of the monograms of early printers and others, eonsvilt: Brulliot, Dictionnairc dcs monogramiiies (Mu- nich, 1832-34) ; Home, Introduction to liihliog- Vol. XIII.— 47. raphy, vol. ii. (Loudon, 1814); Herbert and Ames, Typographical Antiquities (ib,, 1749); Leutsch, i'nircrsal Monogram-Work (Gera, 1803) ; Schiller, Monogramme (Ravensburg, 1897 et seq.). MONOGRAP'TTJS (Xeo-Lat.. from Gk. ijJ>ms, monus. single + ypairrbt, graplus, marked with letters, from ypdcpe.v, graphcin, to write). A genus of extinct graptolites found in and char- acteristic of rocks of Silurian age. See Grap- TOLITE. MO'NO LAKE. A lake in .Mono County, east central California. It lies in the Sierra Nevada at an altitude of 0730 feet, and is surrounded by mountains rising 0000 to 7000 feet above its surface (Map: California, D 2). Its area is now about 85 square miles, but ancient beaches show that it was formerly nearly four times as large. It has no outlet, and its waters are so salty that fish cannot live in them. Sodium carbonate and bicarbonate constitute nearly one-half of the salts held in solution, and these are therefore of considerable commercial value, MONOLITH (Lat. monolithus, from Gk. IwfSXiBos. consisting of a single stone, from /iii/os, monos, single + XiOos, lithos, stone). A monument, statue, obelisk, column, shaft, or other architectural member formed of a single stone or cut out of the solid rock. Monolithic columnar shafts of large size and highly colored marbles did not become popular with the Romans until the Imperial period. (See Column.) In Egypt, and especially in India, there are examples of monolithic temples, as at Abu-Sinibel, and in the cave-temples and monasteries at Ajanta. El- lora, Karli. etc.. and the open-air monuments at Ellora. Dhumnar, and many other places. Of monolithic blocks in ancient architecture some of the largest are at Baalbek in Syria, one measuring about 70 X 21 X 14 feet. A remark- ably high shaft was one quarried at Vinal Haven, Me., 115 feet high and weighing 150 tons. MON'OMA'NIA (Neo-Lat., from Gk. piivs, monos, single + jiavla, mania, madness). A form of insanity in which there is one sys- tematized delusion which dominates, while it does not impair, the intellect of the lunatic. The central delusion may be replaced in part by minor related delusions, and it may be concealed upon occasions, or for a long period of time. Ability is not incompatible with this form of insanity. MONOMETALLISM. See Bimet.llism; MONEV. MONONGAHELA, mA-non'ga-he'li. One of the headstreams of the Ohio River. It rises in the Alleghany Mountains in Randolph County, West Virginia, and flows northward with many windings through a fertile and populous valley abounding in coal and timber (Map: Pennsyl- vania, B 4). .-t Pittsburg, Pa., it joins the Allegheny River to form the Ohio. Its total length is" about 300 miles, and by a system of nine locks it has tjeen made navigable for steam- boats to Morgantown, W. Va., 100 miles above Pittsburg. Four more locks are now in con- struction above Morgantown. and the Govern- ment plans to nuike the river navigable to Fairmount in Marion County, at the junction of its two main headsireams. The principal tribu- tarj' is the navigable Youghiogheny. On the
