352 THE BEAUTIES OF NATURE CHAP, 
trary, though more richly peopled in its upper 
layers, which swarm with such innumerable 
multitudes of living creatures that they are, 
so to say, almost themselves alive — teems 
throughout with living beings. 
The deepest abysses have a fauna of their 
own, which makes up for the comparative 
scantiness of its numbers, by the peculiarity 
and interest of their forms and organisation. 
The middle waters are the home of various 
Fishes, Medusa, and animalcules, while the 
upper layers swarm with an inexhaustible 
variety of living creatures. 
It used to be supposed that the depths of 
the Ocean were destitute of animal life, but 
recent researches, and especially those made 
during our great national expedition in the 
“Challenger,’ have shown that this is not 
the case, but that the Ocean depths have a 
wonderful and peculiar life -of their own. 
Fish have been dredged up even from a depth 
of 2750 fathoms. 
The conditions of life in the Ocean depths 
are very peculiar. The light of the sun can- | 
not penetrate beyond about two hundred 
