. THE HOUSE MOUSE 653 



ance. Finally the mouse made a third exit over the trap ; 

 we stamped the floor loudly, and (rather sorrowfully) saw the 

 frightened little beast jump on to the trap in trying to return 

 to its home. If alarmed in a room, a mouse will usually try 

 to reach its hole by running round close to the wall, or along 

 the top of the skirting, seldom taking a direct course across 

 the floor. 



Though usually extremely timid, the House Mouse some- 

 times, when not molested, will show a certain amount of 

 impudent boldness. We know of one case where a mouse 

 entered a paper bag containing biscuits, and began to nibble 

 them, with much rustling, within a few inches of a man lying 

 in bed reading.^ We knew an actor who used to eat a lonely 

 and frugal supper long after midnight. One night a mouse 

 climbed on to the cloth at the other end of the table, and 

 finding our friend both harmless and hospitable, it became a 

 regular visitor. Nor is such audacity exhibited before man 

 alone, for Mr Beavan mentions mice running between the 

 legs of the Golden Eagles and scampering over the Tiger 

 at the Zoo. 



The eyes of the House Mice are described by Prof, 

 C. V. Boys {Nature, ist February 191 2, 447) as being 

 " autophanous " ^ — shining pale ruby or rather spinel — and 



' Mr Cocks («« lit.) says : — " One night, soon after I had fallen asleep, I was 

 awakened by a mouse sitting on my pillow, nibbling my hair (I use no lubricant). 

 I stealthily put my arm up and made a grab, but not being able to see it, besides, 

 perhaps, being hardly fully awake, I missed the mouse, which jumped off the bed 

 and ran away. I soon fell asleep again, but before long was again awakened by 

 the mouse eating my hair ; the process as just described was repeated not only that 

 once but two or three more times, at intervals of perhaps half an hour or rather 

 longer. At last I made rather a better shot and touched the mouse, though again 

 failing to secure it, and it finally disappeared. The mouse no doubt was ravenously 

 hungry." 



^ The term " autophanous " was introduced by Col. J. Herschel {Nature, i8th 

 Jan. 1912, 377) to describe eyes which (like those of cats and dogs) appear to emit 

 light, by shining when seen in the dark. Such eyes are, of course, not autophanous 

 at all (as Herschel points out) ; they merely reflect light which is seen when the eye 

 of the observer is nearly in line with the illuminating source ; and they act exactly 

 as do the "reflex lights" used by cyclists. When the retina is backed by black pig- 

 ment, as in normal men and monkeys, the eye is not autophanous, but forms the best 

 possible means for obtaining sharp and clear vision. When the pigment is lacking, 

 the retina rests directly upon a burnished surface — the tapetum ; the eye is then 

 autophanous ; and while clearness of vision is impaired, the greatest possible power 

 of detecting motion, in objects under observation, is conferred. 



VOL. II. 2 T 2 



