HARPER: TrIP ON WARRIOR AND TOMBIGBEE RIVERS 109 
have been selected, for we enjoyed ideal weather most of the time, 
and entire freedom from mosquitoes; and although not many 
plants along the river were in bloom, there were few if any which 
were not in the right condition for identification. 
One of the indirect effects of civilization in Alabama is that locks 
and dams now have to be provided in the larger rivers to make navi- 
gation possible at all seasons.* Thereare to be nine locks between 
Tuscaloosa and Jackson when the contemplated river ‘ improve- 
ments’”’ are completed, but at the time of our trip the second and 
third (counting from tide-water) were unfinished, and all our diffi- 
culties were in the part of the Tombigbee to be served by them, a 
distance of not quite fifty miles. This system of locks, while it 
seems to be an economic necessity, is a detriment to science in 
more ways than one. In the first place, it seriously interrupts the 
normal life-history or physiographic development of the rivers, 
and, what was of more concern to our party, it has permanently 
covered the lowest few feet of one of the most important bluffs 
with an opaque screen of muddy water.t 
The Warrior River has its sources among the Carboniferous 
plateaus of northern Alabama, leaves the highlands at Tuscaloosa, 
and at Demopolis, 130 miles farther down, joins the Tombigbee, 
which derives most of its water above that point from the Creta- 
ceous region of western Alabama and northeastern Mississippi. 
The Warrior between Tuscaloosa and Demopolis probably aver- 
ages a little less than 100 yards in width, and the Tombigbee be- 
tween Demopolis and Jackson a little more. In most of what 
follows the two rivers will be treated as one, the fact that the 
name of the lower portion continues up the western instead of the 
eastern branch at Demopolis being more or less arbitrary or acci- 
dental. After passing through Tuscaloosa County this river forms 
a — boundary the rest of the way to the Gulf, { passing the 
Locks for 1 navigation are practically unknown in the other southeastern states, 
a ne because those states have much less heavy freight, such as coal and cement, 
to export than Alabama has, and also partly because most of the navigable rivers in the 
other states could not be dammed up much without flooding large areas. 
+ The only known station in Alabama for Hymenocadlis coronaria (see Mohr, 
Contr. U. S. Nat, Herb. 6: 447. 1901) nih probably been destroyed by this time, 
by the same proc 
tItis J lass largely for this reason that there are no wagon bridges across it 
below Tuscaloosa County. 
