In conclusion, I deem it in order to offer a few remarks with regard to the causes of death among these apes, and to the proper treatment of the animals in captivity. We know so little and assume so much concerning them that we often violate the very laws under which they live.

We have already noticed the fact that the gorilla is confined by nature to a low, humid region, reeking with miasma and the effluvia of decaying vegetation. The atmosphere in which he thrives is one in which human life can hardly exist. We know in part why man cannot live in such an atmosphere and under such conditions, but we cannot say with certainty why the ape does do so. It would seem that the very element that is fatal to the life of man gives strength and vitality to the gorilla.

We know that all forms of animal life are not affected in the same way by the same things, and while it may be said in round numbers that whatever is good for man is good for apes also, it is not a fact.

The human race is the most widely distributed of any genus of mammals and, as a race, can undergo the greatest extremes of change in climate, food and other conditions of any other animal. His migratory habits, both inherent and acquired, have fitted him for a life of vicissitudes, and such a life inures him as an individual to all extremes. On the other hand, the gorilla, as a genus, is confined to a small habitat, which is uniform in climate, products and topography; and having been so long restricted to these conditions he is unfitted for like changes, and when such are forced upon him the result must always be to his injury.

In certain parts of the American tropics there is found a rich, grey moss growing in great profusion in certain localities and on certain kinds of trees. It is not confined to any certain level, but thrives best on the lowest elevations. Under favourable conditions it will grow at altitudes far above the surrounding swamps. The character and quantity, however, are measured by the altitude at which it grows. It is an aerial plant, and may be detached from the boughs of one tree and transplanted upon those of another. It may be taken with safety for a great distance so long as an atmosphere is supplied to it that is suited to its nature; but when removed from its normal conditions and placed in a purer air it begins to languish and soon dies. If it be returned in time, however, to its former place or one of like character it will revive and continue to grow.

What element this plant extracts from the impure air is a matter of doubt; but it cannot be carbonic acid gas which is the chief food of plants, nor it cannot be any form of nitrogen; and it is well known that the plant cannot long survive in a pure atmosphere. Whatever the ingredient extracted may be, it is certain that it is one that is deadly to human life, and one which other plants refuse. Moisture and heat alone cannot account for it.

We have another striking instance in the eucalyptus, which lives upon the poison of the air around it. There are many other cases in vegetable life, and while the animal is a higher organism than the plant, there are certain laws of life that obtain in both kingdoms which are the same in principle.

Between the case of the gorilla and that of the plant there is some analogy. It may not be the same element that sustains them both, but it is possible that the very microbes which germinate disease and prove fatal to man sustain the life of the ape in the prime of health. The poison which destroys life in man preserves it in the ape.

The chimpanzee is distributed over a much greater range, and is capable of undergoing a much greater degree of change in food and temperature. The history of these apes in captivity shows that the chimpanzee lives much longer in that state and requires much less care. From my own observation I assert that all of these apes can undergo a greater range of temperature than they can of humidity. This appears to be one of the essential things to the life of a gorilla, and one fatal mistake made in treating him is furnishing him with a dry, warm atmosphere, and depriving him of the poison contained in the malarious air in which he spends his entire life. Both of these apes need humidity. The chimpanzee will live longer than a gorilla in a dry air, but neither of them can long survive it, and it would appear that a salt atmosphere is best for the gorilla.

I believe that one of these apes could be kept in good condition for any length of time if he were supplied with a normal humidity in an atmosphere laden with miasma and allowed to vary in temperature. A constant degree of heat is not good for any animal, there is nowhere in all the earth that nature sustains a uniform degree of it. We need not go to either extreme, but a change is requisite to bring into play all the organs of the body.

The theory of their treatment which I would advance is to build them a house entirely apart from that of any other animal. It should be 18 or 20 feet wide by 35 or 40 long, and at least 15 feet high. It should have no floor except earth, and that should be of sandy loam or vegetable mould. In one end of this building there should be a pool of water 12 or 15 feet in diameter, and embedded in the mould under the water should be a steam coil to regulate the temperature as might be desired. In this pool should be grown a dense crop of water plants such as are found in the marshes of the country in which the gorilla lives. This pool should not be cleaned out or the water changed, but the plants should be allowed to grow and decay in a natural way. Neither the pool nor the house should be kept at a uniform heat, but allowed to vary from 60 to 90 degrees.

In addition to the things mentioned, the place should be provided with the means of giving it a spray of tepid water, which should be turned on once or twice a day, and allowed to continue for at least an hour at a time. The water for this purpose should be taken from the pool, but should never be warmer than the usual temperature of tropical rain. The animal should not be required to take a bath in this way, but should be left to his own choice about it.

The house should be separated by a thin partition that could be removed at will, and the other end of the building from the pool should be occupied by a strong tree, either dead or alive, to afford the inmates proper exercise. The rule that visitors or strangers should not annoy or tease them should be enforced without respect to person, time, or rank. No visitor should be allowed on any terms to give them any kind of food. The reasons for these precautions are obvious to any one familiar with the keeping of animals, but in the case of a gorilla their observance cannot be waived with impunity.

The south side of the house should be of glass, and at least half of the top should be of the same. These parts should be provided with heavy canvas curtains, to be drawn over them so as to adjust or regulate the sunlight. In summer-time the building should be kept quite open so as to admit air and rain. The ape does not need to be pampered: on the contrary, he should be permitted to rough it. Half of the gorillas that have ever been in captivity have died from over-nursing. By nature they are strong and robust if the proper conditions are supplied, but when these are changed he becomes a frail and tender creature. They should not be restricted to a vegetable diet nor limited to a few articles of food of any kind, but should be allowed to select such things as they prefer to eat. I have grave doubts as to the wisdom of limiting the quantity. One mistake is often committed in the treatment of animals, and that is to continue the same diet at all times and limit that to one or two items. It may be observed that the higher the form of organism is the more diverse the taste becomes, and while very hardy animals or those of low forms may be restricted to one staple kind of food, the higher forms demand a change.

One thing above all others that I would inhibit is the use of straw of any kind in their cage for beds or any other purpose. If it be desired to furnish them with such a comfort, nothing should ever be used but dead leaves if they can be supplied. In their absence a canvas hammock or wire matting should be used. There are certain kinds of dust given off by the dry straw of all cereal plants. This is deleterious to the health of man, but vastly more so to these apes. It is taken into the lungs, and through them act upon other parts of the body by suppressing the circulation and respiration. No matter how clean the straw may be, the effect will be the same in the end. Hay is better than straw, but even this should not be used.

Another thing which is necessary is to entertain or amuse them in some way, otherwise they become despondent and gloomy. It is believed by those who are familiar with these apes that loneliness or solitude is a fruitful cause of death. This is especially so with the gorilla. I have a photograph of one that was kept by a trader on the coast of Africa for nearly three years. She was devoted to him, and was never content when not in his company. His business required him to make a journey of a few days to the interior. He left the gorilla at his place on the coast where she had lived up to this time. The day after he departed she became morose and fretful, and within a few days died without any apparent cause except pining. This was observed by natives and by white traders, and her death has always been ascribed to the cause assigned. She was well known to all the traders on that part of the coast, and has been regarded as one of the best specimens known. She is the only one that I have ever known to become devoted to a human being.

Another important fact that is little known but very singular is, that tobacco smoke is absolutely fatal to a gorilla. Every native hunter that I met in Africa testifies that this simple thing will kill any gorilla in the forest if he is subjected to the fumes for a short time. I have reason to believe that it is true. It may not prove fatal in every instance, but it will in many. The chimpanzee is not so much affected by it, although he dislikes it, but the gorilla detests it and shows at all times his strong aversion to it. I have no doubt that this is one of the reasons that these apes always die on board the ships by which they are brought from Africa.

Both of these apes are possessed, in a degree, of savage and resentful instincts. But these are much stronger in the gorilla than in the chimpanzee. He therefore requires firm and consistent treatment. This can be used without being severe or cruel, but the intellect of the gorilla must not be underrated. He studies the motives and intentions of man with a keen perception, and is seldom mistaken in his interpretation of them. He often manifests a violent dislike for certain persons, and when such is discovered to be the case the object of his dislike should not be permitted in his presence, for the result is to enrage the ape and excite his nervous nature. When they become sullen or obstinate they should not be coaxed or indulged, nor yet used with harshness. They should either be left alone for the time or diverted by a change of treatment.

At this point I submit the foregoing to the world as the sum of my labours in this special field of research up to this time. I regret that I have been compelled to deny much that has been said, but I make no apology for having done so. In this work I have sought to place these apes before the reader as I have seen them in their native forest. I have not clothed them in fine raiment or invested them in glamour, but I trust that this contribution may be found worthy of the respect of all men who love Nature and respect fidelity.

I have the vanity to believe that the methods of study which I have employed will be made the means of farther research by more able students than the writer.

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