tliat, -when taken again to the lowlands, the Al- jiiiic features were not lost for a long time. In general, the adaptations of Alpine plants are sim- ilar to those of Arctic plants, but it has been noticed that the leaves are thinner and show more differentiation, intercellular spaces are fewer, and palisade cells better developed. Hairy ])lants are perhaps more characteristic of Alpine than of Arctic regions. The Alpine conditions are peculiar and are chiefly due in the last analysis to the rarefied air. The consequent decrease in pressure has probably a direct effect on vegetation, but experiments have not yet made this clear. In any event, the thin air causes a greatly increased in- tensity of heat and light by day, and a great- ly increased radiation of heat by night. Tlius gi'eat extremes of temperature are the rule. The rarity of the air also prevents great rain- fall. These conditions, together with exposure to wind, work in harmony toward the develop- ment of a highly xerophytie flora, as has been previously mentioned, and it is easy to see how none but xerophytes can survive in such a loca- tion. The differences between Arctic and Alpine conditions may be summed up thus: Arctic light is more constant, but less intense, and this perhaps accounts for the differences in leaf structure and color intensity in Arctic and Alpine regions, as stated above. The changes of temper- ature are more rapid in Alpine districts. The xerophytie structures of Alpine plants are per- haps due to causes set in operation by thin air, while in Arctic plants the causes may be set in operation rather by the cold or even frozen soil. See also Mountain Plant, and the plate sliowing Alpine Vegetation, accompanying this article.
ALPINI, al-pe'ne, Prospero (1553-1617). A Venetian botanist and physician. He antici- pated Linna!us in determining the sexual differ- ences of plants, and one of his papers gave Europe the first notice of the cofl'ee shrub. He filled the chair of botany in the University of Padua for many years. His best known work is De Plantis .Jigyp'ti (Venice, 1592; Padua, 1G40). The genus Alpinia is named after him.
ALPINIA. See Galangale.
ALPS. The word Alp is of Celtic origin, and signifies, according to some authorities, "white," and according to others, "high." Thus the Alps may be simply the White Mountains, or the High Mountains. The name is applied to a mountain system of Southern Europe, which in- cludes most of Switzerland, and extends into France on the west, Austria on the cast, Italy on the south, and Germany on the north, and covers ahxigether an area of some 80,000 to 90,000 square miles (Map: Europe, D 4).
The system rises from the shore of the Mediter- ranean west of the Gulf of Genoa, and at first trends northward to the west of the plain of Lombardy; then swinging to the east, it stretches with an east and west trend through Switzer- land and across the north of Italy into .ustria. The total length of the system is upward of 600 miles, and its breadth ranges from about 75 to about 150 miles. It contains hundreds of peaks exceeding 10,000 feet, and its crowning summit, Mont Blanc, has an altitude of 15,781 feet. In the extreme northeast, where the Al- pine system reaches the Danube, it is met by a range belonging to the great system of the Car- patiiian and Sudetic Mountains. On the west the Alps are connected with the Jura Mountains. In the soutli the Apennines form a great con- tinuation, extending as far south as Sicily. The Cevennes in southeastern France constitute in a measure a connecting link with the Pj-renees. The range of mountains known as the Dinarie Alps, on the borders of Dalmatia and Bos- nia, are a connecting link between the Alpine system and the Balkan Mountains. The slopes upon the south, to the plains of Lombardy, are much more abiiipt than those on the north to the lower lands of Switzerland and Aus- tria. This bi-oad, complex mountain region is the source of many of the great rivers of Europe.. The western slope of that part of the range which trends north from the Mediterranean shore is drained into that sea by the Rhone, while the east slope of this part, together with the southern slope throughout Italy, is drained into the Adriatic mainly liy the River Po. The north slope is drained into the North Sea by the Rhine, and into the Black Sea by the Danube, which flows around the eastern end of the moun- tain system. The head branches of these rivers, aided by the glaciers at their sources, have erod- ed this mountain mass into a complex of short ranges and ridges, many of which have received distinctive names.
Subdivisions. The Alps are commonly, but rather arbitrarily, divided into three port.ions. The Western Alps comprise that portion having a north and south trend, and extending north- ward to the Great St. Bernard Pass; the Central Alps extend thence eastward to the Brenner Pass, while the Eastern Alps include the remain- der. In the Western Alps the ranges and ridges are broken and irregular, while in the other parts of the system the secondary ranges trend more commonly parallel to the axis of the sys- tem. The system is still further subdivided into groups or ranges separated from one another more or less completely by stream gorges. The following groups are comprised in the Western Alps: The Maritime Alps, near the Slediterra- nean coast: the Cottian Alps, stretching from Slont Chameb,Ton. 11,155 feet, to the Col de Frejus. It contains several peaks exceeding 12,- 000 feet in height. West of it is the small group known as Oisans, with Mont Pelvoux, 12,970 feet, and Les Ecrins, 13,462 feet, the highest peak of Dauphine. The Graian Alps are the northernmost group of the Western Alps; here are Grand Paradis, 13,324 feet; Mont Pourri, 12,428 feet; La Grivola, 13.028 feet: the Grands Coulvirs, 12,567 feet; the Grande Sassi&re, 12,- 430 feet; and, at the turning point of the range, Mont Blanc, 15,781 feet.
The Central Alps are subdivided into many groups, of which only the principal ones can be mentioned. The Bernese Alps separate the up- per valley of the Rhone from the Aar, and com- prise many well known peaks, among them the Jungfrau, 13,672 feet: Finsteraarhorn, 14,026 feet; Aletschhorn, 13,720 feet; Miinch, 13,465 feet: Eiger, 13,040 feet: Schreckorn, 13.385 feet, and Wetterhorn, 12,150 feet. This is one of the most rugged groups of the system, contain- ing many peaks exceeding 12,000 feet in height, and having many glaciers, one of which, the Aletsch, is the longest in the Alps. On the op])osite side of the Rhone valley is another splendid range, the Pennine Alps, in which, grouped about Zermatt, are the Matterhorn or Mont Cervin, 14,780 (14,705) feet; Weisshorn,
