From 67@ 30' to 90@, twenty-two degrees and a half of latitude
remained to travel; that is, about five hundred leagues.
Hence we may suppose that the organisms now living under the climate of latitude 60 deg, during the Pliocene period lived further north under the Polar Circle, in latitude 66 deg-67 deg; and that the strictly arctic productions then lived on the broken land still nearer to the pole.
But I do not doubt that some temperate productions entered and crossed even the lowlands of the tropics at the period when the cold was most intense,--when arctic forms had migrated some twenty-five degrees of latitude from their native country and covered the land at the foot of the Pyrenees.
According to the narrative of the German doctor, Ferdinand Werne, the expedition attempted in 1840, under the auspices of Mehemet Ali, stopped at Gondokoro, between the fourth and fifth parallels of north latitude.
In ancient times, the ambassadors of Nero reached the ninth degree of latitude, but in eighteen centuries only from five to six degrees, or from three hundred to three hundred and sixty geographical miles, were gained.
They next made for the first of the great lakes, the one named Tanganayika, situated between the third and eighth degrees of south latitude.
There Burton, who was completely worn out, lay ill for several months, during which time Speke made a push to the northward of more than three hundred miles, going as far as Lake Okeracua, which he came in sight of on the 3d of August; but he could descry only the opening of it at latitude two degrees thirty minutes.
Ferguson carefully remarked that they had not gone beyond the second degree of south latitude, nor the twenty-ninth of east longitude.
This mount, situated in 9@ north latitude
and 20@ east longitude, rose to a height of 10,600 feet above the surface of the moon.