94 ANIMAL LIFE OF THE BRITISH ISLES. 



during the year, each consisting of five or six, or even up to 

 twelve, blind and naked young which develop so rapidly that 

 in a fortnight they are capable of independence. At the age of 

 six weeks they may begin to breed. 



The House Mouse exhibits a considerable range of variation 

 in colour, both darker and lighter than the type, and many of 

 these variations have been bred from and their peculiarities per- 

 petuated and accentuated in confinement as " fancy " mice. Of 

 these the most familiar are the White Mice, really albinos with 

 pure white fur, pink eyes, feet, and tail. There are also dark, 

 nearly black variations, and spotted examples. Sometimes one 

 is surprised at night to find that the house is tenanted by a 

 musical mouse that runs up the scale in what appears to be an 

 attempt at a little song. It has been ascertained, however, 

 that these so-called singing mice are afflicted with a form of 

 asthma, and the supposed vocal efforts are merely the mani- 

 festation of their physical trouble. We have had experience of 

 musical mice in another way. For several nights in succession 

 weird sounds came from the pianoforte which suggested that 

 fairies were using it as a harp, twanging the wires instead of 

 striking them with the hammers. An examination of the 

 interior seemed to indicate the actual performer, for a little pile 

 of Spanish nuts, stolen from the table, was discovered inside ; 

 and the twanging of the notes was caused probably by the 

 mouse climbing them. A trap baited with a shelled nut put a 

 stop to these performances. Bateson mentions several cases of 

 hairless Mice, except for a few whiskers. 



A local race of the House Mouse found in St. Kilda is some- 

 times dignified with species rank under the name of Mus 

 muralis. Its distinguishing features include less slender feet 

 and tail, and slight peculiarities of the palate. 



