After entering the Mississippi, below Sandy Lake, the stream presents very much the character it has above. It was below this point that we first observed the juglans nigra in the forest. Its banks are diluvial or alluvial formations, elevated from six to ten feet. The elm, maple, and pine are common. There are some small grassy islands, with tufts of willows, and driftwood lodged. No rock strata appear. The river winds its way through vast diluvial beds, exhibiting at its rapids granitical, quartz, and trappose boulders. It appears to glide wholly over the primitive or crystalline rocks, which rise in some places through the soil, or show themselves at rapids. The expedition descended the stream twenty-eight miles, and encamped on a sandy elevation on the west shore, near Alder River, which seemed to promise an exemption from the annoyance of insects; but in this we were mistaken. In the hurry of a late encampment, it had been omitted to pitch the tents. The first ill effect of this was felt on being awakened at night by rain. A humid atmosphere is ever the signal for awakening hordes of insects, and the mosquitos became so troublesome that it was impossible to sleep at all after the shower. We got up and whiled away the time as best we could around the camp-fire. We embarked a few minutes before 5 A. M., the morning being lowering and overcast, which eventuated in rain within an hour. The atmosphere resumed its serenity, and the sun shone out at noon. The river, as on the preceding day, has its course between alluvial and diluvial banks, sweeping its way over the smooth orbicular beds of the granitical age. The influx of rivers, the occurrence of islands, which bear witness of their entire submersion during the freshets, and the succession of bends, points, and rapids--these changes, with notices of the wild fowl, forest birds, and sometimes a quadruped, or a mass of boulders, absorbed my notices, which it seems unimportant, at this time, to refer to. No fixed stratification of rocks was encountered this day. We encamped at about eight o'clock, on the east bank, on an open eminence, just below the rapids which mark the confluence of Pine River, having been in our canoes, with very brief and infrequent landings, fifteen hours. At the points of landing, I observed the rosa parviflora, and ipomea nil. As night approached, we heard the monotonous notes of the caprimulgus virginianus. We had also observed during the day, the bald eagle, king-fisher, turdus polyglottis, teal, plover, robin, and pigeon. The nimble sciuris vulgaris was also observed on shore. Boulders of sienite, hornblende rock, silicious slate, sandstone, and quartz, served as so many monuments to testify that heavy oceanic currents had heretofore disrupted the northern stratification, and poured down over these long and gradual geological slopes.