18 EXTINCT MONSTERS. 
found collected together the bodies of 9 black cattle, 3 horses, 
1840 sheep, 45 dogs, 180 hares, together with those of many 
smaller animals, also the corpses of two men and one woman. 
Humboldt, the celebrated traveller, says that when, at certain 
seasons, the large rivers of South America are swollen by heavy 
rains, great numbers of quadrupeds are drowned every year. 
Troops of wild horses that graze in the ‘‘savannahs,” or grassy 
plains, are said to be swept away in thousands. 
In Java, in the year 1699, the Batavian River was flooded 
during an earthquake, and drowned buffaloes, tigers, rhinoceroses, 
deer, apes, crocodiles, and other wild beasts, which were brought 
down to the coast by the current. 
In tropical countries, where very heavy rains fall at times, and 
rivers become rapidly swollen, floods are a great source of danger 
to man and beast. Probably the greater number of the bodies 
of animals thus drowned find their way into lakes, through 
which rivers flow, and never reach the sea ; and if the growth of 
sediment in such lakes goes on fairly rapidly, their remains may 
be buried up, and so preserved. But in many cases the bones 
fall one by one from the floating carcase, and so may in that way 
be scattered at random over the bottom of the lake, or the bed 
of ariver at its mouth. In hot countries such bodies, on reach- 
ing the sea, run a great chance of being instantly devoured by 
sharks, alligators, and other carnivorous animals. But during 
very heavy floods, the waters that reach the sea are so heavily 
laden with mud, that these predaceous animals are obliged to retire 
to some place where the waters are clear, so that at such times 
the dead bodies are more likely to escape their ravages; and, at 
the same time, the mud with which the waters are charged falls 
so rapidly that it may quickly cover them up. We shall find 
further on that this explanation probably applies to the case of 
the ‘‘ fish-lizards,” whose remains are found in the Lias formation 
(see p. 51). 
But, for several reasons, sedimentary rocks formed in lakes 
