THE WILD WEST—COSSACKS AND WILD WESTERS.—In pursuance with their intention to assemble together at the Chicago Fair, a congress of the horsemen of the world, Messrs. Cody and Salsbury have commenced to form the neucleus of the same, as will be seen by the arrival and appearance in conjunction with the cowboy, Mexican, Indian, vaquero, &c., at Earl's Court, of a band of genuine Cossacks from the Caucasas. As the season advances apace, the plot of interest thickens progressively, for the crowds who assemble daily to enjoy the attractions of the Earl's Court International Horticultural Exhibition and Buffalo Bill's Wild West. Cossacks in the picturesque garb of the Caucasas is the latest acquisition of the Wild West. They are a troop of "Cossacks of the Caucasian line," under the command of Prince Ivan Makharadze. The Prince and his comrades, it is interesting to the British public to know, belong to the same branch of the great Cossack family, the Zaporogians, immortalised by Byron's "Mazeppa." Mazeppa was the hetman or chief, of the Zaporogian community of the Cossacks of the Ukraine.