Cuap. VII. MURA INDIANS. 157 
however, numerous varieties intermediate between the two are found, 
so that we are compelled to consider them as local modifications of one 
and the same species. The difference between the two local forms is 
of a slight nature, and many naturalists on this account alone would 
consider them to belong to the same species ; but the numerous existing 
intermediate shades of variation show how many grades are possible 
between even two local varieties of a species. In fact, the steps of 
modification are found to be exceedingly small and numerous in all 
cases where the filiation of races or species can be traced; and this 
circumstance may be held as confirming the truth of the axiom, “‘ Natura 
-non facit saltum,” which has been impugned by some writers. 
About two miles beyond this sand-bank was the miserable abode of 
a family of Mura Indians, the most degraded tribe inhabiting the banks 
of the Amazons. It was situated on a low terrace on the shores of a 
pretty little bay at the commencement of the high barreiros. With the 
exception of a ciuster of bananas there were no fruit-trees or plantation 
.of any description near the house. We saw in the bay several large 
alligators, with head and shoulders just reared above the level of the 
water. ‘The house was a mere hovel ; a thatch of palm-leaves supported 
on a slender framework of upright posts and rafters, bound with flexible 
lianas, and the walls were partially plastered up with mud. A low door- 
way led into the dark chamber, the bare earth floor was filthy in the 
extreme ; and ina damp corner I espied two large toads whose eyes 
glittered in the darkness. The furniture consisted of a few low stools ; 
there was no mat, and the hammock was a rudely woven web of ragged 
strips of the inner bark of the Mongtiba tree. Bows and arrows hung 
from the smoke-blackened rafters. An ugly woman, clad in a coarse 
petticoat, and holding a child astride across her hip, sat crouched over 
a fire roasting the head of a large fish. Her husband was occupied in 
notching pieces of bamboo for arrow-heads. Both of them seemed 
rather disconcerted at our sudden entrance ; we could get nothing but 
curt and surly answers to our questions, and so were glad to depart. 
We crossed the river at this point, and entered a narrow channel 
which penetrates the interior of the island of Tupinambardana, and leads 
to a chain of lakes called the Lagos de Cararaucu. A furious current 
swept along the coast, eating into the crumbling earthy banks, and 
strewing the river with débris of the forest. ‘The mouth of the channel 
lies about twenty-five miles from Villa Nova ; the entrance is only about 
forty yards broad, but it expands, a short distance inland, into a large 
sheet of water. We suffered terribly from insect pests during the twenty- 
four hours we remained here. At night it was quite impossible to sleep 
for mosquitoes : they fell upon us by myriads, and without much piping 
came straight at our faces as thick as raindrops in a shower. The men 
crowded into the cabins, and then tried to expel the pests by the smoke 
from burnt rags, but it was of little avail, although we were half 
suffocated during the operation. In the daytime the Mottica, a much 
larger and more formidable fly than the mosquito, insisted upon levying 
his tax of blood. We had been tormented by it for many days past, but 
this place seemed to be its metropolis. The species has been described 
by Perty, the author of the entomological portion of Spix and Martius’ 
