This classification applies to the higher wild animals, quite as truly as to men. By the manager of wild animals in captivity, wild-animal temperament universally is recognized and treated as a factor of great practical importance. Mistakes in judging the temper of dangerous animals easily lead to tragedies and sudden death. Fundamentally the temperament of a man or an animal is an inheritance from ancestors near or remote. In the human species a morose or hysterical temperament may possibly be corrected or improved, by education and effort. With animals this is rarely possible. The morose gorilla gives way to cheerfulness only when it is placed in ideally pleasant and stimulating social conditions. This, however, very seldom is possible. The nervous deer, bear or monkey is usually nervous to the end of its days. The morose and hysterical temperaments operate against mental development, progress and happiness. In the human species among individuals of equal mental calibre, the sanguine individual is due to rise higher and go farther than his nervous or lymphatic rivals. A characteristic temperament may embrace the majority of a whole species, or be limited to a few individuals. Many species are permanently characterized by the temperament common to the majority of their individual members. Thus, among the great apes the gorilla species is either morose or lymphatic; and it is manifested by persistent inactivity and sullenness. This leads to loss of appetite, indigestion, inactivity and early death. Major Penny's "John Gorilla" was a notable exception, as will appear in Chapter IX. The orang-utan is sanguine, optimistic and cheerful, a good boarder, affectionate toward his keepers, and friendly toward strangers. He eats well, enjoys life, lives long, and is well liked by everybody. Except when quite young, the chimpanzee is either nervous or hysterical. After six years of age it is irritable and difficult to manage. After seven years of age (puberty) it is rough, domineering and dangerous. The male is given to shouting, yelling, shrieking and roaring, and when quite angry rages like a demon. I know of no wild animal that is more dangerous per pound than a male chimpanzee over eight years of age. When young they do wonders in trained performances, but when they reach maturity, grow big of arm and shoulder, and masterfully strong, they quickly become conscious of their strength. It is then that performing chimpanzees become unruly, fly into sudden fits of temper, their back hair bristles up, they stamp violently, and sometimes leap into a terrorized orchestra. Next in order, they are retired willy-nilly from the stage, and are offered for sale to zoological parks and gardens having facilities for confinement and control.