CONTRACTILITY OF COLOUR-SPECS. 101 



the animal ;" especially when such a leap in logic had 

 to be taken as is taken at the " therefore V Physiolo- 

 gists are, indeed, extremely facile in their admission of 

 " the will " to explain what they do not understand ; 

 but we must marvel that direct observation did not 

 utterly discountenance its introduction here ; for it is 

 quite certain that hundreds must have seen, if they did 

 not ohserve, what most attracted me in the matter — 

 namely, the appearance and disappearance of the 

 colour-specs in the skin of the dead animal ; and even 

 the most metaphysical of zoologists would hardly attri- 

 bute volition to a corpse. The observation of this one 

 fact mio'ht have led to further investio-ation. On 

 placing a small strip of the skin under the Microscope, 

 I was surprised to find two or three of these colour- 

 specs expanding and contracting with great vigour. 

 At first I thought it must be an optical illusion, but on 

 close attention it became too decided for doubt ; and 

 not suspecting the truth, I concluded that some ani- 

 malcidae were imbedded in the tissue, and that their 

 movements produced this apparent activity of the 

 globules. To settle these doubts, two other strips 

 underwent examination ; in both of these, all, or al- 

 most all, the specs were in activity, shooting out pro- 

 longations, and retracting again — two specs sometimes 

 seeming to run into one, but really overlapping each 

 other, and sometimes a point not bigger than a millet 

 seed expanding to the size of a sixpence, growing 

 fainter in colour as it expanded. This was decisive. 

 If the globules in a strip of skin taken from the dead 



