FEOM PARA TO MANAOS. 169 
former to make collections, the latter to attend to the 
repairs of his photographing apparatus, which has met 
with some disasters. We are all to meet again at Manaos 
for our farther voyage up to Tabatinga.* We remained 
at Santarem only long enough to see the party fitted out 
with a canoe and the necessary supplies, and as they put 
off from the steamer we weighed anchor and proceeded 
on our way, reserving our visit to Santarem for our return. 
As we left the port the black waters of the Tapajoz met 
the yellow stream of the Amazons, and the two ran together 
for a while, like the waters of the Arve and Rhone in 
Switzerland, meeting but not mingling. Instead of return- 
ing at once to the main river, the Captain, who omits 
nothing which can add to the pleasure or the profit of our 
voyage, put the steamer through a narrow channel, which, 
on the Mississippi, would be called a " bayou," but goes 
here by the name of an " Igarape." Nothing could be 
prettier than this " Igarape Assu," hardly more than wide 
enough to admit the steamer, and bordered on either side 
by a thick wood, in which are conspicuous the Munguba, 
* I soon became convinced after leaving Para that the faunas of our different 
stations were not repetitions of each other. On the contrary, at Breves, Taja- 
purii, Gurupa, in short, at each stopping-place, as has been seen, we found 
another set of inhabitants in the river, if not wholly different from the last, 
at least presenting so many new species that the combination was no longer 
the same. It became at once very important to ascertain whether these dif- 
ferences were permanent and stationary, or were, in part at least, an effect 
of migration. I therefore determined to distribute our forces in such a way as 
to keep collecting parties at distant points, and to repeat collections from the 
same localities at different seasons. I pursued this method of investigation 
during our whole stay in the Amazons, dividing the party for the first time at 
Santarem, where Messrs. Dexter, James, and Talisman separated from us to 
ascend the Tapajoz, while Mr. Bourget remained at Santarem, and I, M \th the 
rest of my companions, kept on to Obydos and Villa Bella. L. A. 
8 
