DOWN THE AMAZOXS. 371 
of the tropics may produce upon laminated clays of recent 
origin the same effect as plutonic agencies have produced 
upon the ancient clays, that is, it may change them into 
metamorpliic slates. As I approached the serra, I was 
a<rain reminded how, under the most dissimilar circum- 
O * 
stances, similar features recur everywhere in nature. I 
came suddenly upon a little creek, bordered with the usual 
vegetation of such shallow watercourses, and on its brink 
stood a sand-piper, which flew away at my approach, utter- 
ing its peculiar cry, so like what we hear at home that, 
had I not seen him, I should have recognized him by his 
voice. After an hour's walk under the scorching sun, I 
was glad to find mvself at the hamlet of Erere, near the 
C5 */ ' 
foot of the serra, where I rejoined my companions. This 
is almost the only occasion in all my Amazonian journey 
when I have passed a day in the pure enjoyment of nature, 
without the labor of collecting, which in this hot climate, 
where specimens require such immediate and constant at- 
tention, is very great. I learned how rich a single day may 
be in this wonderful tropical world, if one's eyes are only 
open to the wealth of animal and vegetable life. Indeed, a 
few hours so spent in the field, in simply watching animals 
and plants, teaches more of the distribution of life than a 
month of closet study ; for under such circumstances all 
things are seen in their true relations. Unhappily, it is not 
easy to present the picture as a whole ; for all our written de- 
scriptions are more or less dependent on nomenclature, and 
the local names are hardly known out of the districts where 
they belong, while systematic names are familiar to few." 
January 30^. On board the " Ibicuhy." Yesterday 
we parted from our kind hosts, and bade good by to Monte 
Alegre. I shall long retain a picture, half pleasant, half sad, 
