LIFE IN TEFF& 249 
t 
tbo /ate of about a foot a day. It was easy to measure its 
retreat by the effect of the occasional rains on the beach. 
The shower of one day, for instance, would gully the sand 
to the water's edge, and the next day we would find the water 
about a foot below the terminus of all the cracks and ruts 
thus caused, their abrupt close showing the line at which 
they met the water the previous day. Ten days or a fort- 
night before we left, and during which we had heavy 
rains at the close of every day, continuing frequently 
through the night, those oscillations in the river began, 
which the people here call " repiquete," and which, on 
the Upper Amazons, precede the regular rise of the water 
during the winter. The first repiquete occurs in Teffe 
toward the end of October, accompanied by almost daily 
rains. After a week or so the water falls again ; in ten 
or twelve days it begins once more to ascend, and sinks 
again after the same period. In some seasons there is a 
third rise and fall, but usually the third repiquete begins 
the permanent annual rise of the river. On board the 
steamer we were joined by Mr. Bourget, with his fine 
collections from Tabatinga. He, like both the other par- 
ties, has been hindered, by want of alcohol, from making 
as large collections as he might otherwise have done ; but 
they are, nevertheless, very valuable, exceedingly well put 
up, and embracing a great variety of species, from the 
Maranon as well as from the Hyavary. Thus we have a 
rich harvest from all the principal tributaries of the Upper 
Amazons, within the borders of Brazil, above the Rio Negro, 
except the Purus, which must be left unexplored for want 
of time and a sufficient working force. 
On leaving Teffe I should say something of the nature 
of the soil in connection with Mr. Agassiz's previous 
11* 
