BONE-CAVES OF MALTA. 
437 
least, along the central portion of this water area wandered 
herds of divers species of elephants, whilst the same shell- 
fish lived on the land and in the sea, and with many of the 
mammals survived all the great changes that have since taken 
place. Many of the animals have no doubt been driven back, 
and in part annihilated through man ; s agency ; still not a few 
have disappeared from the face of the earth by means far 
beyond his most powerful energies. How, and by what 
manner of way, has this been accomplished? The answer 
must, at least for the present, remain ambiguous until we are 
better able to estimate the length of time represented by the 
evidences, and more is known of the laws which regulate the 
growth, decay, and final extermination of animated beings. 
