The advantages of the union of Upper and Lower Canada gradually became so manifest, that a convention was held at Quebec in 1864 for the purpose of considering the advisability of uniting all the provinces. The result bore fruit in the passage of an Act of Union by the British Parliament on March 29, 1867, under which Ontario, Quebec, New Brunswick and Nova Scotia were formally united as the Dominion of Canada, the actual event being consummated on July 1, 1867. Subsequently, on July 20, 1871, the Colony of British Columbia, and on July 1, 1873, the Colony of Prince Edward Island, were added to the Dominion. In 1869 the vast territories of the Hudson's Bay Company were acquired by purchase, and out of them the province of Manitoba was formed and admitted to full privileges in the Dominion on July 15, 1870. The absorption of the Company's Territories is interesting for, as we all know, this was a trading concern whose sole commodity was fur. The Arctic and sub-Arctic regions of the continent were the mecca of hunters and trappers, and their chief prey from the time the first French explorers began to search the Canadian lakes, and later when the Hudson's Bay Company succeeded to the French domain, was the beaver. In fact the early history of Canada was largely bound up with beaver catching and the sale of the skins, and for nearly a century the northern territories, both under French and English rule, were organized with a view to this traffic. In the early days of the Company the "standard of trade" of the Northwest was a beaver skin. Thus the beaver naturally became emblematic, which resulted later in its use as the "crest" of the Canadian coat-of-arms, a place that it retains to the present day over those of the Dominion. In this connection it would be unjust to omit a mention of that other symbol dear to the Canadian heart--the maple leaf. Like the rose, the thistle and the shamrock of the Mother land, the beautiful tree of the Colony, so widespread, so useful, and so gorgeous in its autumn coloring of red and gold--the blazon of the English arms--became a favorite emblem of the people. The particular variety that is so used is of course the rock or sugar maple (_acer saccharinum_).