1889.] The Song of the Singing Mouse. 
disposition observed by Tafani 1889, 
48, 116, in mice ova at this staj^e ; 
Tafani describes each cell as having 
the form of a three-sided pyramid 
with the apex at the centre of the 
ovum and a convex base forming 
part of the external surface of the 
yolk. That the two first cleavage 
planes are meridional is rendercii ^^ 
probable by the arrangement in the 
four cell stage observed by Selenka ^''^'- '*^ 
in the Virginian oppossum. (Fig. 10.) after 
THE SONG OF THE SINGING MOUSE. 
IN the daily papers and in scientific journals references to 
singing mice are not uncommon, some relating to wild 
species, but generally to the house mouse. The authors of 
these notices usually refer to the mice as singing from happy 
choice, as if they greatly enjoyed their own music, and in cap- 
tivity, they have been reported as singing when food was given 
them, or when turning the wheel, as expressive of delight and 
high spirits. In some cases a mouse may be able to sing at 
will, but I think, from the descriptions I have read, that it is 
generally involuntary, as it certainly was in the individual that 
came under my own observation. 
Several years ago, in November, I heard a strange noise 
near some water pipes in a store room, and at first thought 
that one of them had broken, and that a little stream was 
gurgling between the walls. However, later on, this gurgling 
noise was found to be produced by a mouse, which ran from 
behind various boxes as they were, in turn, removed, keeping 
J. A trap was set, and after a few days the 
, captured. In the meantime, it was heard at inter- 
