ON THE AMAZON. 87 
still imperfectly known. The Rio Negro has dense moist forest on 
each side all the way up, therefore contains few or no Orchises ; though, 
from the absence of mosquitos, &c., it is undoubtedly pleasanter to 
travel on than the Solimoes. Mr. Bentham told me the Tapajoz had 
been explored, otherwise my own inclinations would prompt me to 
ascend it, for it is much the most romantic of the tributaries of the 
Amazon, its serras extending even to its mouth, at Santarem, while the 
- mountains at its source are the highest in Brazil. Mr. Hislop speaks ' 
with enthusiam of the number and abundance of the Ferns near the 
cachoeiras. Does Mr. Bentham know the particulars of its exploration ? 
Mr. Hislop recollects a party of Germans (among whom was a natu- 
ralist) coming rapidly down the Tapajoz; but you know that no one 
gathers half so much in coming down a river or mountain that he does 
in going up. I have a capital opportunity of getting up, all the way 
to Cuyaba if I like, with a merchant who came down lately with a 
cargo of gold and diamonds. 3 
The Rio Chiquitos is an upper branch of the Madeira, between 15° 
and 20° 8. latitude. I suppose Humboldt means that all the country 
between the Amazon, the Madeira, and the Andes, is imperfectly known 
as to its vegetation, which I believe to be the case. 
T am glad to hear that Gramineæ and Cyperacee will be acceptable 
in Europe: the Grasses here are very interesting, those on the sandy 
campos and volcanic serras being quite a different set from those on the 
river-banks and low lands. Para was a better place for Cyperacee, 
and now is the best time for them. I shall have a few things for your 
museum when I send the plants, but as my funds require to be eeono- 
mically dealt with, I cannot purchase many things. 
The Mandiocca-plants grow to six or seven feet, and would pro- 
bably grow higher; I have never seen them —— without lens. 
lup AE 1850. : 
When I arrived at Santarem last October, I hired the only house 
that was vacant (for houses are more scarce here than elsewhere in the 
province); but it suited me very well, for it has a spacious verandah 
at the back, where we could work at our plants, and a. paved yard, 
where we could spread our paper, &e., to dry. The adjoining house 
was tenanted by a single man, and we were very quiet; but when we 
retumed from Obidos we found it tenanted by a family, from several 
days up the Tapajoz, including amongst them, besides children, several 
