ars was crowded with valuable experiences of
one sort and another. Some of the most toilsome journeys proved only a
disappointment, while others brought success beyond his most sanguine
dreams. At the end of two years it was agreed between himself and Bates
that they should separate, Wallace doing the northern parts and
tributaries of the Amazon, and Bates the main stream, which, from the
fork of the Rio Negro, is called the Upper Amazon, or the Solimoes. By
this arrangement they were able to cover more ground, besides devoting
themselves to the special goal of research on which each was bent.

In the meantime, Wallace's younger brother, Herbert, had come out to
join him, and for some time their journeys were made conjointly; but
finding that his brother was not temperamentally fitted to become a
naturalist, it was decided that he should return to England.
Accordingly, they parted at Barra when Wallace started on his long
journey up the Rio Negro, the duration of which was uncertain; and it
was not until many months after the sad event that he heard the
distressing news that Herbert had died of yellow fever on the eve of his
departure from Para for home. Fortunately, Bates was in Para at the
time, and did what he could for the boy until stricken down himself with
the same sickness, from which, however, his stronger constitution
enabled him to recover.

Perhaps the most eventful and memorable journey during this period was
the exploration of the Uaupes River, of which Wallace wrote nearly sixty
years later: "So far as I have heard, no English traveller has to this
day ascended the Uaupes River so far as I did, and no collector has
stayed at any time at Javita, or has even passed through it."

From a communication received from the Royal Geographical Society it
appears that the first complete survey of this river (a compass traverse
supplemented by astronomical observations) was made (1907-8) by Dr.
Hamilton Rice, starting from the side of Colombia, and tracing the whole
course of the river from a point near the source of its head-stream. The
result showed that the general course of the lower river was much as
represented by Wallace, though considerable corrections were necessary
both in latitude and longitude. "I am assured by authorities on the Rio
Negro region," writes Dr. Scott Keltie to Mr. W.G. Wallace, under date
May 21, 1915, "that your father's work still holds good."

In May, 1852, Wallace returned to Para, a