GRASSHOPPER SPARROW. 149 GRASSMANN. resemble those of a locust or a "grasshopper." The C'uimnouest one is the yellow-winged spar- row {Ammodrainus jiasserinus) , which is about live inches long, pale brown and streaked iu cclor, with the front edge of the wing conspicu- ously yellow, and which conceals itself most of the time in the held and roadside herbage. See Spaukow. GRASSHOPPER WARBLER. A European warbler (Locustclla nwcia), common in Great Britain. It haunts the reedy banks of streams, where it conceals itself and its nest with great skill among the herbage. Its notes are almost the same as those of a locust. It appears erro- neously in many books as 'grasshopper lark,' but i.s of the family SylviidiB, and not at all related to the larks. GRASSI, gras'se, Battista. A Sicilian natur- ali>t. professor of zoijlogy in the University of Rome. Several years were devoted by him to the bionomics and ' life-history of the wliite ants ■(Termitid;e). He discovei'ed (1893-90) that the young are all born alike, and that the dilTerences between the workers, etc.. when heredity or selection does not operate, result from differences in the food. He also proved that an individual can by change of food be made into a soldier after it has visibly undergone one-half or more of its development into a winged sexual form. He, with Calanduccio, proved' in 1887-96, what had already been suspected in 1864 by Gill, that a minute fish. Leptocephalus. is the larva of the eel. and that females of eels can mature only in depths of at least 500 meters. For these dis- coveries he was elected a foreign member of the Eoyal Society of London. His researches, made in "l898-1900! on the sporozoan malarial parasite of the mosquito (see Sporozoa) are of great scientific and practical value. He independently proved that the mosquito (Anopheles) transmits malaria, and that, by the use of wire gauze as a covering for windows, doors, and chimneys of houses, the worst malarial regions of Italy can be rendered as healthy as any other part of the country. He also proved the transmission of filariiV of the blood by the same Anopheles {Anopheles claviger) which is the host of this micro-parasitic worm. GRASSLANDS. One of the three great cli- matic landscape types — deserts, forests, grass- lands — into which Schimper, in his work on plant geography, divides the world. It is not yet clear- ly known what determines the presence of trees or of grasses in a given locality. Schimper, per- haps, has the most tenable hypothesis for the origin of grasslands, viz. that they occur in regions where dry winter winds preclude the presence of forests. Since grasses are shallow- rooted, they do not require a moist subsoil, such as trees do. and since they are of low stature, they are protected from the desiccating influence of wind. The greatest development of grasslands is in the temperate zone, and commonly in Con- tinental interiors. Ecologically speaking, the pure climatic grasslands of the world are essen- tially similar, though the species found in them vary with the country. In different lands, as is well known, they have various names, of which those that have come to be of most im- portance to students of phytogeography are prairie, steppe (qq.v.l. and pampas. One speaks of the pampas of Argentina, the prairies of North America, and the steppes of Europe and Asia, lu all these, however, the general life- conditions are similar, and there is no essential reason for more than one title. A type of forma- tion which differs essentially from that just described is the savanna (q.v.), which is inter- mediate between forest and grassland, and is located in a transitional climate. Many of the llanos and campos of Xorthern South America are true savannas, while others are essentially grasslands. In general, savannas are as charac- teristic of tropical regions as pure grasslands are of temperate. Again, there are edaphic grass- lands, e.g. river meadows and swamps of lake origin. Through the influence of man, many arti- ficial grasslands are to be found, e.g. pastures and most meadows. Perhaps edaphic river sa- vannas are to be classed here also. See Distbi- liUTioN OF Plants. GRASSMANN, griis'man, Hermann GUn- TiiEB (1809-77). A German mathematician and Sanskrit scliolar, born at Stettin. He was a son of Justus Giinther Grassmann (died 1852 at Stettin ) , who was well known for his work in crystallography. The young Grassmann devoted his attention at first to theology and philosophy, which he began studying in Berlin in 1827. He then turned his energies to mathematics, which he taught successively at the industrial school in Berlin, at the Ottoschule in Stettin, and at the Stettin Giunasium. He is known chiefly for his work Die Wissenschaft der extensiven Grossen Oder die Ausdehnungslelire (1844, and later edi- tions). The obscure style of this treatise was such as to cause the first edition to pass prac- tically unnoticed, and it was not until the theory of quaternions (q.v.) began to be recognized that Grassmann's allied theory- attracted attention. In later life he took up the study of Sanskrit, and published a ^yo7■terbuch ^hhi Rigieda (Leip- zig, 1875), which is a remarkable e.ample of a combined dictionary and concordance, and is still indispensable to all Sanskrit scholars, and an Uebersetzung des Rigveda (2 vols., 1870-77), which is based on the principles of the so-called linguistic school of Vedic interpretation, and is likewise a work of much value. Grassmann was also the discoverer of one of the most important laws of comparative linguistics, which is still known as Grassmann's law (q.v.). His other works include the following: ""Neue Theorie der Elektrod™amik"' ( PoggendorfT's Aimalen, vol. 64) ; "Theorie der Farbenmischung" (same jour- nal, vol. 89) ; Geo-metrische A-nnlyse. gekniipft an die von Leibniz erfnndene geometrische Charak- teristik (1847); Lehrbuch der Arithmetik iind Trigonometrie (1861-65). A collection of his works on mathematics and physics was published at Leipzig in 1894. Consult Schlegel, H. Grass- mann, scin heben und seine fVcrke (Leipzig, 1878). GRASSMANN, Robert (1815-10011. A Ger- man niatln'matician. a brother of Hermann Grass- mann (q.v.). He was born at Stettin. After devoting himself for several years tn teachinrr. he went into journalism, and became associated as writer with the Stettiner and the Pommerschr Zeituiig. His researches, especially those on the theory of arithmetic, are important, and reveal considerable originality. He also wrote a number of works on special sciences, includ- ing: Die Formenlehre oder Mathematik (1872) ;
