Beyond that there was no light; plant life disappeared and with it the herbivorous animals.
The submarine grade, a gentle one down to this point, now becomes very steep, descending rapidly to the oceanic abysses,--that immense mass of water (almost the entire ocean), without light, without waves, without tides, without currents, without oscillations of temperature, which is called the "abyssal" zone.
In the littoral, the waters, healthfully agitated, vary in saltiness according to the proximity of the rivers.

The rocks and deeps are covered with a vegetation which is green near the surface, becoming darker and darker, even turning to a dark red and brassy yellow as it gets further from the light.

In this oceanic paradise of nutritive and luminous waters charged with bacteria and microscopic nourishment, life is developed in exuberance.

In spite of the continual traps of the fishermen, the marine herds keep themselves intact because of their infinite powers of reproduction.
The fauna of the abyssal depths where the lack of light makes all vegetation impossible, is largely carnivorous, the weak inhabitants usually devouring the residuum and dead animals that come down from the surface.

The strong ones, in their turn, nourish themselves on the concentrated sustenance of the little cannibals.
The bottom of the ocean, a monotonous desert of mud and sand, the accumulated sediment of hundreds of centuries, has occasional oases of strange vegetation.