According to Chapman, many of the notes of birds are language notes rather than sounds expressive of sentiment. Of the robin this well-known student of birds says: ‘The song and call-notes of this bird, while familiar to everyone, are in reality understood by no one, and offer excellent subjects for the student of bird language. Its notes express interrogation, suspicion, alarm, and caution, and it signals to its companions to take wing. Indeed, few of our birds have a more extended vocabulary.’ Winchell says that the common English sparrow has as many as seven different notes, which it uses to express the thoughts and feelings passing through its rather active but not very highly honoured head: (1) The common note of address of the male to the female; (2) a note of alarm used by both male and female adults, but never by the young; (3) an emphatic alarm note, always uttered by sentinels when a hawk is near or when a man approaches with a gun; (4) the note of the female when surrounded by several noisy and contending male rivals; (5) an autumn cry uttered by the first one of the company perceiving danger and flying up from the hedges and fields—never uttered by young, but by adults of both sexes; (6) the love note of both male and female, used mostly by the female, and generally with a fluttering or shaking accompaniment of her wings; (7) a curious note sometimes heard in London—meaning not well understood, but supposed to be a sort of chuckle or sign of contentment. Each one of these several different notes may be used to stand for various ideas depending on the circumstances by being given different emphasis and inflection, just as in the languages of many primitive races of men a small vocabulary of words is used to stand for a much larger number of ideas by being pronounced differently. In the Chinese language, for instance, the words are increased to three or four times the original number by modulation; but the same thing is observed in all languages, both human and non-human. Verbal poverty is pieced out by verbal variation. We say ać-cent or ac-cent́, depending on whether we wish to express the idea of a noun or a verb.