ON THE CUTANEOUS PIGMENTARY SYSTEM OF THE FROG 67 
post mortem concentration came on as usual, that the pigment-cells retain 
their powers, and also their capability of acting in mutual harmony after the 
rhythmical contractions of the heart have been abolished by this poison. 
Such experiments are so readily performed, and the effects produced upon 
the pigment-cells or the nerves which govern them are so obviously indicated 
by the changes of colour in the integument, that I venture to recommend this 
method of investigation to those who are occupied in studying the action of 
poisons. 
