the distance from the equatorial circle in the other. This decrease in temperature exerts so great an influence over plants that few species are found to be common to places widely differing either in latitude or altitude.

Soil is another influential agent in the limitation of species and the modification of individuals; some plants being peculiarly adapted to certain kinds of soil, and rarely found growing in any other, while others, although they may exist, present a puny and sickly appearance when found growing in soils not adapted in texture and composition to their nature.

Moisture also is of the utmost importance to the well-being of all cellular bodies, as well vegetable as animal; and is in fact so much a necessity that when deprived of it they cease to live. These three agencies are those which have played the most important part in diversifying the vegetation of the globe; but two of them, viz.: temperature and moisture, present themselves under a somewhat peculiar aspect in Acadia.

In its relation to the ocean, this region differs from all New England and Canada; and while holding an intermediate place between the two, is open to climatic influences peculiar to itself.

The renovation of the ocean by the interchange of waters throughout its vast expanse, is affected through the medium of ocean currents, flowing alternately to and from the poles. Such of these "ocean rivers" in the northern hemisphere as flow northward, are continually thrown further and further east as they approach the arctic circle, by the retarded rotation of the earth from west to east; while such as run southward are thrown to the west. Hence, while Europe is bathed in the warm waters of the Gulf stream, running in a long are northward across the Atlantic, the polar current, having a westerly momentum, clings to the American coast, and Acadia not only shares the cool climate prevalent along this seaboard, but owing to its semi-insular position, has its temperature still further lowered. This is strikingly evident when the climate of St. John is compared with that of cities in Europe-such as Bordeaux, Turin and Venice,-under the same parallel of latitude. The principal cause of this difference of temperature is the fact that here we have on the north-east a refrigerator in the Gulf of St. Lawrence, traversed as it is by a branch of the polar current, which, entering at the Straits of Belleisle, sweeps around the shores of the Lower Provinces and

finds an outlet in the Gut of Canso and further east. We have also a cool vapor bath in the sea fogs, which in summer bathe our south-eastern shores, and whose influence on vegetation will be noticed in the sequel. Thus it may be seen that within the limits of these Maritime Provinces there are variations of temperature, which mere extent of surface or elevation of land will not account for, but which are mainly dependent on ocean currents and their concomitants.

Not only the coldness, however, but the humidity of the atmosphere in many parts of Acadia, exercises a powerful influence upon its flora.

It is a well-known fact that the land and sea breezes which alternately fan districts bordering the sea in inter-tropical regions, result from the periodical heating and cooling to which such lands are subject every twenty-four hours. Analogous to this is the prevalence of certain sets of wind on the coast of large areas of land in temperate latitudes, during the summer, and of others during the winter months.

Mr. G. Murdock, in a paper on the Meteorology of St. John, read before this Society in 1863, pointed to this phenomenon as exhibited in the vicinity of this city, in the following words: "In the wind columns, it is observed that the increase and duration of southerly weather follows very nearly that of the temperature. July is the month of maximum southerly weather, and December of minimum. From July to December, there is a constant diminution, and from this latter month to July again a steady increase." Of these southerly winds, the south-west is by far the most frequent, and, if continuous, sooner or later brings upon the southern coast of Acadia those fogs for which St. John is notorious.

During each of the two hottest months of the year, St. John is enveloped for nearly a week in constant fog; and this misty curtain, by its presence, not only excludes the direct rays of the sun, but by its coolness lowers perceptibly our summer temperature.

During the months of July and August there is also a large rainfall, and if we add to the rainy and foggy days those which are cloudy, but nineteen days out of the two mid-summer months remain during which the sun shines upon us in unclouded splendor.

If we give due weight to these sources of humidity and cold, and consider, also, that our position on the sea-side is an additional cause of a diminished temperature, we need feel no surprise at the

sub-arctic summers which prevail at St. John, nor at the sub-arctic type of vegetation which flourishes around us. It is well known that humidity, in its influence over the distribution of Arctic plants, in a limited degree represents cold. But when a climate is both cool and moist, as ours is, it presents a double attraction to these little northern adventurers.

Having seen what a chilling effect these south-west winds, with their accompanying fog and rain, have at the coast, let us now follow the same breezes into the interior.

As soon as the fogs pass the coast, they are rapidly absorbed by the atmosphere (expanded by warmth radiated from the heated earth), and may be traced in their progress inland, in the long banks of cumuli-clouds which hang over the southern hills; and are finally dissipated entirely in the onward progress of the southerly winds, which now possess nearly the original warmth and most of the moisture that they had when first they began their journey from the Gulf Stream. Now pre-eminently invigorating and refreshing, these winds course onward toward the shore of the Gulf of St. Lawrence, stimulating the growth of many species of plants, which cannot abide their chilling influences at the coast. As may be inferred, they bear a very different reputation along the Gulf from that which attaches to them with us. In spring and early summer they blow down the valleys of the Miramichi, and other streams debouching on that coast, as warm breezes, prevalent during the night and morning, giving a great stimulus to vegetation; but in the evening they are pushed back, or forced upward by a strong, cold wind from the Gulf, but lately relieved from its wide fields of floe-ice. The latter (N. E. winds) often blow with much violence about four or five o'clock in the afternoon, and such is their chilling influence that flowers which have been in bloom in Fredericton for a fortnight are (about 1st June) only opening their petals on the Miramichi. There is nearly the same difference between St. John and Fredericton at this period, although the first flowers of spring, such as the Mayflower (Epigaa repens) usually opens with us a little in advance of their time of flowering at the capital. The advent of spring is undoubtedly first felt at St. John, but the increase of fog and chilly winds in the month of May checks the growth of plants with us, while the very same winds give an increased impetus to their growth and expansion in the interior, where, at the 1st of June, vegetation,

in its summer development, is a fortnight in advance of the coast, and subsequently much more.

The valley of Cornwallis, in Nova Scotia, has a summer mean of sixty-five degrees, and it is probable that a large area in the interior of Continental Acadia will be found to have, at that period, a temperature equally high. At Fredericton "ninety degrees in the shade" is not rare, and at Woodstock the mercury is said to rise to one hundred degrees Fahrenheit.

As there is no systematic register of the heat of this region accessible, it is necessaay to bear in mind the prevalence of the south-west winds in summer time, in order to judge of the diverse influences which this important agent exercises over the growth of plants in the interior as compared with its effect upon the vegetation of the coast.

Of soils, Continental Acadia possesses a great variety, which have a proportionate influence with the causes already noted upon the range of plants within its borders.

The Highlands, both north and south, being mainly made up of metamorphic rocks, which are comparatively impervious to water, the drainage of the soil upon them is thereby much impeded. Hence, it happens that, notwithstanding the hilliness of these districts, there are, especially in the southern hills, numerous peatbogs, interspersed with bare rocky tracts known as "barrens.” These barrens extend for many miles along the coast of the Bay of Fundy, where granite and hard metamorphic rocks prevail, and where the natural drainage is imperfect, and the soil scanty and unproductive. The drier portions are covered with a profusion of ericaceous shrubs, etc., such as blue-berries (Vaccinium Pennsylvanicum), Labrador Tea (Ledum latifolium), Leather Leaf (Cassandra calyculata), Sheep Laurel (Kalmia augustifolia), Rhodora Canadensis, etc. In the swamps, and on mossy slopes, knee-deep with sphagnum, grow the Sweet Gale (Myrica Gale), Marsh Rosemary (Andromeda polifolia), Cranberries (Vaccinium oxycoccus), etc. The larger depressions are occupied by peat bogs, or lakes and ponds, with which such tracts are often studded. There is a striking resemblance in the aspect of these barrens, dotted as they are with numerous little sheets of water, and interspersed with belts and clumps of evergreen trees, to the open tracts in Newfoundland, and to the region occupied by Laurentian rocks in the Provinces of Quebec and Ontario.

The arable lands along this coast are chiefly clay flats, usually covered with terraced beds of sand. The soil on the ridges is mostly gravelly, and here the forest growth is of Black and Yellow Birch (Betula lenta et excelsa). Beech, Maple, and other forest trees of the interior are seldom or never seen. Beneath the shade of the evergreen growth on the clay flats we find the Twayblade (Listera cordata), the Mitrewort (Mitella nuda), the Rattlesnake plaintain (Goodyera repens), the Dwarf orchis (Platanthera obtusata), the one-flowered Pyrola (Moneses uniflora), and other shade-loving plants.

We have seen that the prevalence of a moist climate and impervious soil, coupled with a low temperature, give rise to thick evergreen forests, peat-bogs and swamps saturated with moisture; and while producing, even during clear weather, great radiation of heat and moisture, these causes have contributed to encourage the growth of such northern plants as those above mentioned on the maritime slopes of our southern hills.

On the declension of this hill-country toward the plains of the interior, however, another set of agencies comes into play. It has been already intimated that the summer skies of the central districts are clearer than those of the coast, and the precipitation of moisture less profuse. In the valleys, among the more northerly ranges of the southern hills, much of the soil is loamy, and naturally well drained, as well as fertile. These rich loams are co-extensive with the Lower Carboniferous and Middle Devonian formations in New Brunswick. They border the Lower Plain throughout, fill the valleys of the Kennebeccasis and Petitcodiac Rivers, form islands on it along its north-west side, and re-appear in the valley of the Tobique among the northern hills. The fertility of other loams, such as those of the interval lands on the St. John river, and the upland tracts around Houlton and Woodstock (where the slates are of the Upper Silurian formation) on the Upper Plain, is evidenced by the growth of such species of plants as the Dwarf Ginseng or Ground Nut (Aralia trifolia), Closed Gentian (Gentiani Andrewsii), Showy Orchis (Orchis spectabilis), Bass Wood (Tilia Americana), Desmodium Canadense, the two Osmorrhizas, Wild Ginger (Asarum Canadense), and Butternut (Juglans cinerea.)

It is on these lands in going north from the coast that we meet with a new group of species which range thence up the St. John