97 
to be largely pollinated by these little bright-feathered visitors. 
Looking down the valley from the vantage point of a mountain 
flank, one saw amid the dark-green masses of vegetation dazzling 
spots of henna orange, where two or three giant Erythrina trees 
reared their domes of almost leafless branches, clothed with sprays 
of tango-hued flowers, while far up the dry mountain flanks the 
bromeliad-laden trees made great sweeps of Corot gray. Giant 
grasses (Gynerium saccharoides), related to the pampa grass, 
made canebrakes here and there along the Miguilla River, while 
in swampy places giant horsetails (Equisetum), an inch through 
and six feet high, made it easy to visualize the Calamites swamps 
of our ancient Carboniferous days. The dry, sandy, unshaded 
places in the river bed were covered with a thorny tangle of sensi- 
tive-plant bushes, 3-5 feet high, full of magenta flower clusters. 
Brushing through them, the leafy branches soon appeared almost 
bare and leafless, as also happens in the case of the little sensitive 
plant of our gardens (Mimosa pudica). In some places along this 
stream walnut trees (Juglans bolivicnsis ?) were said to be com- 
mon, and a few nuts resembling our own black walnuts were picked 
up. Little green parroquets were almost as numerous in this val- 
ley as sparrows are here. I often saw their chattering flocks as 
I went about making collections. 
At last the Moseteno Indians arrived from below with the balsa 
rafts, and we packed and made ready for the descent of the Bopi, 
Espia being just a bare spot at the head of the raft navigation 
where the La Paz and Miguilla rivers unite to form the Bopi. 
as light as 
cork. And farther down, where the valleys were broader and the 
sandbars (playas) were more plentiful, these balsa trees (Ochroma 
lagopus) grow in great profusion, as do willows along our own 
plains’ country streams. The rafts, of seven logs each, were lashed 
together two by two, and soon we had the rather thrilling experi-~ 
ence (it reminded me of shooting the shoots or riding the giant 
racers at Coney Island, except one comes through soaking wet) of 
descending the snaky-winding, stony, rapid-encumbered Bopi.. 
Four or five days of this found us at Huachi, a small hacienda—. 

_ once a mission station—at the junction of the Bopi and Cocha- 
_ bamba rivers, which here form the Beni River, a large tributary 
