94 
teresting plant dates only from 1846, yet it was doubtless re- 
marked by the Spanish explorers who visited its habitat as early 
as 1540, and in all probability notes concerning it are to be found 
in their records of travel. 
While our small boats were found to be quite suitable for the 
purposes of the expedition, yet some care was necessary to avoid 
accident. The river was rising by irregular stages, carrying 
Fic. 24. View of Yuma, Arizona, from reservoir hill, with flood of Gila beyond. 
enormous quantities of driftwood including entire trees, and the 
shifting current was cutting into banks and shoals and making 
uriknown hazards for the navigator of a small boat. During one 
part of the trip we rode the actual crest of a rise of a few feet 
during one day, to have it pass us during the night and then to 
overtake it again on the next day in which we were carried over 
So miles in about seven hours with but little rowing. 
When we arrived at a point 10 or 15 miles above Yuma we 
