294 



COLOUR IN NATURE 



with this. The following table shows the results 

 obtained from some of these experiments : — 



PIGMENTS INTRODUCED INTO ALIMENTARY CANAL 



In these cases the Capitellidse are the only forms 

 in which the introduced pigments come to have a 

 marked effect on the coloration. Another case in 

 which the introduced pigment is important in this 

 way is perhaps the case of caterpillars, where the 

 pigment introduced with the food reaches the 

 connective tissues and so the skin. In the general 

 case, however, it would seem that the pigments 

 which normally result from the activity of the liver 

 or "hepatic cells," as well as pigments artificially 

 introduced into the gut, are usually directly eliminated 

 by means of it, and do not become important in 



