1848.] 
ANIMAL LIFE. 
103 
faint idea of it. A little later, and another noise is heard; 
the flies, which had weighed down every blade of grass, 
now wake up, and, with a sounding hum, commence 
their attack upon the fish : every piece that has lain 
a few hours upon the ground has deposited around it 
masses of their eggs as large as walnuts. In fact, the 
abundance of every kind of animal life crowded into a 
small space was here very striking, compared with the 
sparing manner in which it is scattered in the virgin 
forests. It seems to force us to the conclusion, that the 
luxuriance of tropical vegetation is not favourable to the 
production and support of animal life. The plains are 
always more thickly peopled than the forest ; and a tem- 
perate zone, as has been pointed out by Mr. Darwin, 
seems better adapted to the support of large land-animals 
than the tropics. 
In this lake the overseer informed me he had killed 
as many as a hundred alligators in a few days, whereas 
in the Amazon or Para rivers it would be difficult to 
procure as many in a year. Geologists, judging from 
the number of large reptiles, the remains of which are 
found in considerable quantities in certain strata, tell us 
of a time when the whole world Avas peopled by such 
animals, before a sufficient quantity of dry land had been 
formed to support land quadrupeds. But, as it is evi- 
dent that the remains of these alligators would be found 
accumulated together should any revolution of the earth 
cause their death, it w’ould appear that such descriptions 
are founded upon insufficient data, and that considerable 
portions of the earth might have been as much elevated 
as they are at present, notwithstanding the numerous 
