384 W. J. CROZIER 



in the feeding activity of Stichopus led to the discovery of a 

 somewhat surprising condition. 



Three fairly representative localities were chosen for detailed 

 observation, the places in question being sufficiently near to- 

 gether so that they could be inspected in rapid succession. The 

 first was a shallow, well protected, bight in Crow Lane, immedi- 

 ately to the north of Saltus Island; the second, along the east 

 shore of Agar's Island; the third, along the north side of a narrow 

 ridge of rock projecting westward from an island situated at the 

 mouth of Fairyland Creek. Stichopus was abundant at each of 

 these stations. When the contents of the alimentary tract of a 

 dozen or more specimens from one of these places were examined, 

 it was found that as a rule the great majority of the individuals 

 were in precisely the same condition as regards the presence of 

 ingested mud. At certain times of the day all of the individuals 

 in any one locality were filled to an identical degree. The 

 Stichopus at the different stations were, however, in very differ- 

 ent conditions as regards contained mud. Thus, on several 

 occasions each of 12 Stichopus taken at 8:30 a.m. near Saltus 

 Island was found with the gut completely empty; while those at 

 Agar's Island and at the mouth of Fairyland Creek were uni- 

 formly 'one half full,' the posterior portion of the intestine being 

 empty, although they were collected only a few minutes after the 

 first lot had been obtained. Repeated collections of this sort, at 

 different hours of the day, convinced me that all the holothur- 

 ians in any one locality were usually to be found with the intestine 

 filled to about the same extent. The reason for this curious uni- 

 formity I am not yet in a position to discuss, but it is a condition 

 very useful for the purposes of the problem treated in the present 

 paper. 



The next step consisted in determining the rapidity with which 

 the intestine of Stichopus is filled and emptied. Observations 

 were made in the three localities previously mentioned; the work 

 was of necessity restricted to periods of fine weather. During 

 storms the holothurians do not remain near the surface, but 

 in exposed places, retreat to a depth of several fathoms. They 



