68 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



madreporite of a fresh Echinus was touched with a brush 

 dipped iii formaline. The animal was immediately plunged 

 into fresh sea water to prevent the action of the formaline from 

 spreading beyond the surface of the madreporite. This 

 animal was then examined in sea water with particles in 

 suspension, and no longer gave any suggestion of an outward 

 current through the madreporite. Particles settled freely 

 over its whole surface. 



Obviously any appreciable outward action is due to the 

 cilia on the surface of the madreporite or just inside the madre- 

 poric pores, and not to an outward current. " This, of course, 

 does not disprove a very gentle or an intermittent outward 

 flow, such as one might expect from an excretory organ. 

 Feeding experiments were therefore attempted to settle 

 whether or not any excretory matter finds its way out of the 

 animal through the madreporic system. 



Experiment 4. A dozen Echini were fed with dry 

 methyl blue. They were then kept under observation in 

 running water for several days. No colour appeared anywhere 

 on the surface, and on opening the animals it was found that 

 the methyl blue was simply coated with mucus, and was not 

 being absorbed at all. No results have so far been obtained 

 from any feeding experiment. 



Experiment 5. Dry methyl blue was put into the 

 coelom through a little puncture in the mterambulacral area. 

 The puncture was sealed up with putty and the animal kept 

 in fresh sea water. After one night the whole peristome and 

 the buccal branchiae were bright blue, but no colour appeared 

 anywhere else on the surface, although the animal was kept 

 under observation for many days. Many specimens have 

 been treated in this way and always give the same result. 

 This experiment, like the feeding experiments, gave negative 

 results for the function of the madreporic system. 



Experiment 6. To test for a possible inward current 



