This is the course we pursue when the animal is reared in confined situations: 

As soon as the female has conceived, a quantity of sand and moss is placed on the ground at the side of the water.  This is done without loss of time, that the beast may be accustomed to the sight.  Shortly, if left to herself, she will wallow in the mixture, and as soon as the young one is born, will place it in the sand, covering it over with moss.

As already observed, the female, when running wild in a state of nature, lays the young one in the sand as soon as it is born, covering every part of the body, and then overlaying it with moss.  On this account, we take care to deposit the sand and moss where the animal can easily find them.

The beasts are of a very suspicious nature, and if the sand and moss were not placed near the female until after her young one was born, she would be afraid of them.

The mother is treated with great kindness, and is not allowed in any way to be teased or used harshly.

The hippopotamus is a very nervous animal, and is besides very vicious and irritable.  The female does not easily forget an injury, particularly when with young.  If in any way used unkindly, the effects of the vexation will endure for a long time after the birth of the young one, which will come into the world in a weakly state, and will not thrive.  If it does not soon die, the mother will kill it; for, when ill-treated either before or after parturition, the mother is ordinarily impelled to destroy the calf.  She is often so nervous, that, when with calf, she cannot bear to be looked at and is then placed apart in an enclosure reserved expressly for the purpose, which is hoarded round, and no one but the keeper is allowed to approach her.

In a state of nature, the beast is accustomed to wander over large tracts especially favoured by sun and light; even the water he swims in is warmed by the sun.  In the gardens in which you strive to rear these beasts, they are kept in dark miserable places, where the water is cold, and which the sun rarely penetrates.  You are not kind to them yourselves, and, besides, you allow visitors to tease them.

These errors alone are sufficient to prevent the mother bringing forth a calf that will thrive.

In your cold and variable climates you would do well to have an enclosed place, a kind of conservatory covered over with glass, arranged so as to be opened in warm weather, particularly when the sun shines, and closed during the greater part of the winter, at which time the water, in which the beasts swim, should be warmed by a genial heat diffused through the building.  This plan would be much more profitable than your actual dear economy.

If from any cause it is found judicious to separate the mother and the young one, care should be taken to effect the separation immediately after the birth, before the natural food has been tasted, or at least before it has become familiar to the young one, and the calf should be placed where it cannot hear the mother’s moaning call.