274 THE PLAY OF ANIMALS. 



interesting. The male is coy, the females who visit him 

 sit around him while he growls in a deep base. The 

 others sing tenor, alto, soprano, and every possible part 

 as the chorus mounts, constantly growing wilder. They 

 shake their fists in one another's faces, and will not let 

 even him whom they have come to visit approach them. 

 On clear moonlight nights they make more noise than 

 the wildest urchins." This certainly seems something 

 more than mere sportiveness, and must unquestionably 

 be set down as connected with courtship. Darwin re- 

 gards the cry of the howling ape in the same light, and 

 in addition has this to say about the Hylobates agilis: 

 " This gibbon has an extremely loud but musical voice. 

 Mr. Waterhouse states : ' It appeared to me that in 

 ascending and descending the scale, the intervals were 

 always exactly half tones, and I am sure that the high- 

 est note was the exact octave to the lowest. The qual- 

 ity of the notes is very musical, and I do not doubt 

 that a good violinist would be able to give a correct 

 idea of the gibbon's composition, excepting as regards 

 its loudness.' * This gibbon is not the only spe- 

 cies in the genus which sings, for my son, Francis Dar- 

 win, attentively listened in the zoological gardens to a 

 Hylobates leuciscus which sang a cadence of three 

 notes in true musical intervals and with clear musical 

 tones. It is a more surprising fact that certain rodents 

 utter musical sounds. Singing mice have often been 

 mentioned and exhibited, but imposture has commonly 

 been suspected. We have, however, at last a clear ac- 

 count by a well-known observer, the Rev. S. Lock wood, 

 of the musical powers of an American species, the Hes- 

 peromys cognatus, belonging to a genus distinct from 



* Darwin adds that Owen confirmed this observation. 



