V COLOUR-PHENOMENA IN WORMS in 



regular intervals by the strong circular muscles, so 

 that the stripes which would be formed at the spaces 

 between the longitudinal muscles are interrupted. 



These suggestions are exceedingly interesting and 

 ingenious, and of obvious importance in relation to 

 the origin of markings. In view of the origin of the 

 pigment from the blood, it would be very interesting 

 to know whether it is in any way derived from 

 haemoglobin, and also whether that transfer of pig- 

 ment from the gut to the surface which occurs when 

 the leech is fed with carmine, ever occurs during the 

 ordinary course of affairs. 



The process described by Graf presents some 

 interesting analogies to that described by Eisig for 

 the Capitellidse. An inquiry into the causes which 

 determine the marked differences in colour between 

 the leeches and the Chsetopoda would be very inter- 

 esting, but does not appear to have been attempted. 



The Pigments of the Polyzoa, and the 

 Origin of Pigmentation 



In connection with the colours of worms there 

 are a few points about the pigments of the Polyzoa 

 which are of interest 



The Polyzoa are aberrant worms, which form 

 colonies consisting of numerous polypides embedded 

 in cells or chambers, which, being united together, 

 constitute the ccenoecium or substance of the colony. 

 The coenoecia of Flustra, the sea- mat, are very 

 familiar objects on our own shores, where they are 

 often mistaken for seaweed. Each cell or chamber 

 with its contained polypide is known as a zooecium. 



