Not only man, but some animals--among others a species of mouse found in South Africa--naturally uses his limbs to moderate or strengthen the light of vision. This mouse was observed to shade its eyes with its forepaws in order to look at some distant object under a blazing sun, as we should do in like conditions. In man, whose arms and hands are readily adapted to this primitive art, the habit is common, even among the rudest savages. Putting sight out of the question that we may consider hearing, which is our present theme, reflex movements, either casual or habitual, have certainly induced primitive men to place their hands on the mouth, either so as to suppress the sound or to augment it by using both hands as a kind of shell. It is easy to imagine the use of shells or other hollow objects as a vehicle of sound, either for amusement or some other cause, and these rude instruments might serve as the first step to the invention of wind instruments. Reflection on these spontaneous experiments would readily lead to the search for some mode of prolonging or imitating the voice. In these attempts men might be guided by their observation of the whistle and song of birds, whose beaks may have served as a model for the construction of the flute and reed-pipe. Pott traces the word for sound to the root _svar_, and hence, after some natural phonetic changes, we have in Lithuanian _szwilpti_ for the song of birds. Of all natural objects, different kinds of reeds and the hollow stalks of plants are, owing to their hollow and cylindrical form, best adapted for the imitation of a bird's beak and the sonorous transmission of breath. In many languages the word for a flute is the same as that for a reed. In Sanscrit, _vanca_ and _venu_ mean a flute and bamboo; in Persian, _na_ and _nay_ mean a flute and reed; in Greek [Greek: donas], and in Latin _calamus_, have the same double meaning, and many more examples might be given.