188 BULLETIN NO. VII. 



and with great caution, and had the pleasure of seeing him sit- 

 ting among his corn and singing his beautiful solo. I observed 

 him without interruption, for ten minutes, not over four feet 

 from him. His song was not a chirp, but a continuous song of 

 musical tone, a kind of to wit-to-wee-woo-woo-wee-woo, quite 

 varied in pitch. While I observed him I took for granted that 

 he was a common house mouse (Mus musculus), but when he 

 sprang from the shoe to make his escape he appeared like the 

 prairie mouse (Hesperomys michiganensis), a species I had not 

 however, observed before indoors. I have thus far failed to 

 secure this little rodent musician, but I shall continue to do all 

 I can in the way of popcorn to entertain him, and if his marvel- 

 ous voice gives him the pre eminence in mousedom which he 

 deserves, by the aid of natural selection I shall presently have 

 a chorus of mice; in which case you shall receive their first 

 visit. W. O. Hiskey, Minneapolis, Minn." 



The writer has been informed of many similar cases, making 

 it certain that the musical performances described above, are in 

 no way exceptional, but showing that considerable musical 

 powers are universal among Hesperomys. That the song is 

 not a voluntary expression of pleasure has been suggested by 

 many. The most recent data in favor of the pathological 

 nature of mouse music has been offered by Mr. Davis.* 



While wandering about the house its tell-tale song gave 

 notice of its wanderings. ' ' When removing it from the trap 

 to the cage, and many times afterward, it ran about a small 

 room, and the most noticeable feature on these occasions was 

 the unvaried song, it being especially loud if I caused the mouse 

 to scamper around the room several times without stopping. 

 When gnawing upon the exposed wood in the cage, when eat- 

 ing, or when disturbed in its nest, this singing was particularly 

 loud; in fact, upon any exertion, the song was produced, vary- 

 ing in volume in proportion to the amount of exercise." 



"It was just previous to, and for some time after the birth of 

 two miserable little young that Mus sang most continuously.'' 



It would be of great interest to determine by anatomical 

 examination whether the singing mice are suffering from bron- 

 chial disease. 



*Wm. T. Davis. The Song of the Singing Mouse. Am. Naturalist, 1889, p. 481. 



