This sound of the African night always made the strongest impression upon me, and remains indelibly in my memory. All that one heard from near at hand, or from the distance miles away, had its origin not in man’s voice or in human activity of any kind, but most come from birds and beasts to a great extent unknown to us. One had to interpret, to conjecture, to build up theories. Often one struck upon the correct solution. But often enough, too, the interpretation one accepted proved to be false, and then one’s anxiety to find out the true solution, aroused anew, was doubly keen. The first time I heard it, I had no difficulty in interpreting for myself the cry of the monkeys harassed in the night by leopards, a screaming of a kind one cannot easily forget, plainly expressing the greatest terror. The first time one heard the neighing of the herds of zebras it was much more difficult to recognise the sound, and the gobbling cry of the ostrich had at first a still stranger effect. But as soon as I had heard the voice of the zebras a few times, it was clear to me that the extinct _quagga_ of South Africa must have derived its name from its cry. If one puts the accent on the second syllable, and pronounces the _g_ softly and deep in the throat, one has, as one repeats it, a wonderful reproduction of the cry of the zebra as I heard it myself.[41] What a pity that all this cannot be put on permanent record by some such apparatus as a gigantic phonograph! But unfortunately we are still a long way from such a possibility.