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of the Amazon basin. On the plateaus barley, potatoes, and the 
English broad-bean (Vicia faba) thrive, while the forests of the 
lowland are rich in the familiar plant families of the American 
tropics, 
During the spring of 1921 arrangements were made for the 
writer to conduct botanical investigations in Bolivia as the joint 
representative of the Brooklyn Botanic Garden and The Bussey 
Institution of Harvard University on The Mulford Biological 
Expedition. Under the leadership of Dr. H. H. Rusby, dean of 
the College of Pharmacy of Columbia University, the expedition 
planned to make biological collections, field studies, and explora- 
tions largely on the eastern flanks of the Andes in Bolivia, Brazil, 
and Colombia. Dr. Rusby has long made the Bolivian flora his 
special interest, having made several preceding journeys of botani- 
cal exploration to South America, crossing the continent through 
Bolivia in 1885. The area over which we hoped to work comprised 
that triatgular region of the Amazon river system of which the 
apex is Manaos, and the two basal points, the headwaters of the 
Madeira river system in Bolivia and those of the Rio Negro in 
Brazil and Colombia. Originally we expected to spend fifteen 
months in this work, but, owing to numerous causes, we found it 
necessary to shorten our time to about ten and one half months, 
most of which was spent in Bolivia. 
We sailed from New York on June 1, 1921, landed at Arica, 
Chile, on June 20, and arrived in La Paz, Bolivia, the next day, 
after a trying railroad journey of approximately 21 hours, during 
which an elevation of over 13,000 feet was attained. From La 
Paz our party proceeded by rail to Eucalyptus, where, through the 
courtesy of the Guggenheim Brothers, we were taken by automo- 
bile and mules to Pongo de Quime, one of their power stations on 
the eastern flank of the Andes, the mao road taking us 
through the “ Pass of the Three Crosses ” (Quimza Cruz) at an 
altitude of over 15,000 feet. 
At Pongo our first serious collecting began, and we found it a 
botanist’s paradise, as most of the plants were in bloom. At this 
altitude (10,000 feet) we were as yet too high for trees, but the 
long, narrow, deep valleys were rich in shrubs and herbaceous 
plants. Yellow calceolarias of two species were very common. 
