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gradually undergoing deforestation. Proof is afforded that, at least in this district, the forests have just about held their own. Two hundred and forty years ago, according to the Gyger map, there were 132,500 acres of forests in the Zürich canton. There are

now 120,000 acres of woodlands, or, in other words, the forest area has been depleted only about 10 per cent. since Mr. Gyger made his map. The steeper slopes are still wooded as they were, except here and there where woods have given place to vineyards. The forests have increased on the flood plains of the rivers, and and also on the hill slopes near the Rhine; they have held their own in the northwest part, and in the region of the lower Töss, while the wooded area has been reduced a fourth in the Jona district.

Mr. Gyger also delineated on his map the areas given to wine culture, from which it appears that the increase in the amount of land devoted to this industry at the present time is about 25 per cent. As a rule, wine culture is not attempted now on shaded slopes and at a high altitude to so great an extent as it was two centuries ago.

A very noteworthy recession of the lake area, very little change in the extent of the forests, and an important increase in wine culture in the canton of Zürich are the most important changes which have been brought to light by this interesting comparison of maps. -C. C. A., in New York Sun.

Population of Budapest.-An interesting case in which the growth of a town is shown to be dependent upon the physical features of its location is that of Budapest, noted in The Geographical Journal for January, 1897. This town consists of about 77 square miles of country, largely on the right bank of the Danube. Previous to 1874, Budapest consisted of two towns, Ofen (Buda) and Pest. Since 1840 Ofen, the older town on the mountain side (the best situation for defence) has scarcely doubled its population, while Pest, on the alluvial plain (where agriculture and growth is more possible) on the left bank of the river, has become about six times as large.

R. E. D.





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It is not possible within the compass of a brief paper to set forth adequately the principles of plant geography. I hope, however, within the space allotted me, to demonstrate one or two propositions and suggest directions in which inquiry may be profitable. First of all a few general definitions may be of advantage. Plants, like people, may be regarded individually or collectively. The plant is a vegetable person; the plant-formation is a vegetable community. Just as various degrees of aggregation in human society may be studied-as, for example, the individual, the family, the ward, the city, the state, the nation, the international Bund, the stock, the race-so in plant-society one may distinguish the individual, the family (not in the sense of the systematist), the formation, the aggregate (forest or prairie for example), the flora and the general continental population.

It is highly important to take this fact into the mind: The presence of a given plant at a given point is quite as complicated. a phenomenon in its way as the presence of some particular man at a designated spot. Each fact is a result from a very complex series of natural causes and conditions. Therefore it appears that

plant distribution may be studied from two principal points of view. These are designated (a) floristic plant-geography and (b) ecologic plant-geography. The former provides a census of the kinds of plants in a given region and has its importance; the second provides a rationale for the appearance of particular plants or groups of plants on particular areas. Under the first discipline plants are conceived to be of interest on account of their specific and varietal differences, and extensive lists and analysis rules and terminology have been provided for scientific discrimination of the different sorts of plants in different regions. Descriptive floras are extant, some covering limited areas like counties or public parks, while others, like Bentham and Mueller's Flora Australiensis, cover whole continents. But under the second discipline plants are conceived to be of interest as representing adaptation in all cases to definite though complex environmental influences. The position, relative abundance, life-habits, range and character of the plant are regarded as an expression of certain adjustments between it and its ancestors on the one hand and its past and present surroundings on the other.

Hence there have been indicated what are termed the ecological factors in plant distribution, and the study of these factors in their relation to plants, together with the study of plant stations, habits and ranges constitute what has come to be known as ecologic plant distribution. Among the principal ecologic factors are atmospheric light, heat, vapor-content, wind, precipitation and density; soil illumination, temperature, saturation, cohesion, chemical construction, physical structure and nutritive qualities; also direction of atmospheric, aquatic and soil currents (of the latter avalanches and sliding bogs may be regarded as examples) relief of soil, slope, irregularities, elevation, and all the various conditions termed topographic. Besides these there are the complicated factors depending upon the struggle for existence between individuals, community-groups, formations and aggregates. Thus arise curious relationships like those between the oak and the mistletoe, between the fir-trees and the witches-brooms or between the willow and the dodder. Relations such as these exist also between plants and animals as between the yucca plants and the yucca moth, between leaf-eating ants or boring beetles and the

fungus gardens which they cultivate and upon which they live, between acacias and ants, between clover and bumble-bees, between carrion-fungi and burying beetles, and in a host of ways too numerous to indicate in a short article like this.

In a word, the problem of a plant's location is by no means simple, but demands for its solution the most enlightened knowledge of meteorology, topography, geography, biology and other sciences, together with an accurate general survey of the history of both the species and substratum. To illustrate what I mean, a concrete example, that of certain small cacti of the genus Opuntia, which are established in the valley of the Saskatchewan far north of the bulk of their kind, may be selected. An exact interpretation of their presence on sundry exposed rocky tracts and their habits of life draws one into an examination of the valley as a whole, of the ancient lake Agassiz which once covered the land, of the glacial and post-glacial climate, of the herds of grazing animals—such as the bison, of the arid conditions under which the ancestors of the modern individuals developed their succulence and their spiny armor, and of numerous other matters, all of which have a direct and important bearing upon the question which it is proposed to


It must then be apparent that the explanation of a landscape of forest, swale and meadow is a proper field for scientific as well as artistic endeavor. Notwithstanding the ultimate difficulty of the problems certain general facts can be derived, and these I shall attempt very briefly to develop from fundamental propositions as follows:

The surface of the earth is an exceedingly heterogeneous area occupied by plants and animals. Plants are relatively static organisms in which constructive chemical processes predominate with a consequent tendency rather towards accumulation of matter by synthesis than towards liberation of energy. Animals are relatively dynamic organisms in which destructive chemical processes predominate, with a consequent tendency rather towards liberation of energy by analysis than towards accumulation of matter. Hence, in general, animals are automobile, while plants are not. Hence, also, animals structurally show specialization into an anterior or forward-moving end and a posterior or following-after end

—that is, into head and body. But plants, on the other hand, are structurally specialized into a fixed end and a free end-that is into root and shoot. Hence, further, animals in general develop bilateral symmetry of form, while plants develop radial symmetry and the total weight of all the plants of the world as greatly exceeds the total weight of all the animals, as the dynamic force for equal masses and equal times of such an animal as man exceeds that of a young oak tree.

A broad classification of the earth's surface is into sea and land. Fixity of position becomes more characteristic of land organisms than of aquatic. Hence the fauna is more conspicuous in the ocean, the flora more conspicuous on land. Again both plants and animals may be correspondingly classified as water denizens and land denizens. The inhabitants of the water may be further classified into two main groups, (a) the originally aquatic and (b) the adaptationally aquatic. For example, fish would appear to be originally aquatic, while seals, whales and manatees are adaptationally aquatic. So, among plants, the wrack and gulf weed are originally aquatic, while eel grass, pond lilies and duckweed are adaptationally aquatic. Originally aquatic organisms are those possessing an unbroken line of aquatic ancestors. Adaptationally aquatic organisms are those with more or less remote terrestrial ancestors, but themselves specialized for life in the water. It is interesting to notice that all aquatic flowering plants are adaptationally aquatic. Some, like the water buttercup, show but slight modification from the terrestrial habit, while others, such as the Podostemons are profoundly modified and simulate in appearance the originally aquatic algæ.

An examination of aquatic floras will serve to convince one that adaptationally aquatic plants characterize inland bodies of water and streams rather than the ocean. Thus while fresh-water species of mosses and ferns are known, and occur abundantly, there are none of these plants established in the sea and, save a few flowering plants like Zostera, the oceanic flora consists of originally aquatic algæ. Fresh-water areas, however, being numerous, isolated from each other, existant under various conditions of temperature, illumination, solutions, depth, population and duration in time, have given occasion for a rich series of forms extendng from the artic regions to the equator.

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