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 perpetuated 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 manifestation 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 sometimes 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.
[Pl. 60.]][G 94.
House Mouse.
Mus musculus.
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[Pl. 61.]][G 95.
Alexandrine Rat.
An alien stowaway from North Africa.
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