33 



under these circumstances, to anticipate that these larger pores 

 probably represented the brood chambers of the adult worms, and 

 that the entire corallum was built up by the worms that had been 

 placed so conspicuously in evidence. It is desirable that I should 

 remark at this point that I was at the time unaware of the 

 Alcyonariaii interpretation, that had been associated with 

 Heliopora by Professor Mosaly. The subject was one to which 

 I had not <,nven systematic attention for some .years, and I 

 retained merely a dim recollection that the livinij zooids of the 

 organism had not yet been exhaustively examined. A brief sum- 

 mary ot" the results of my examination of this coral was accord- 

 ingly almost immediately forwarded to the scientific journal, 

 " Nature'' to be followed later by fuller systematic details. 



Meanwhile, a specimen of the Heliopora was placed in a 

 small coral pool at Thursday Island, and was examined from 

 time to time, as the tide and other engagaments permitted, during 

 my visit, for the detection of any new developments. Up to the 

 close of live weeks from the day that the specimen was tirst 

 collected, no alteration was noticed in the external aspect of the 

 coral. The worms, as previously observed, continued to manifest 

 the same state of activity, protruding and extending their 

 tentacles on all sides from the smaller pores, in search of food. 



The afternoon before leaving Thursday Island, a last visit was 

 paid to the coral pool, when to my no small astonishment, zooids, 

 each with eight pinnate tentacles, were seen protruding from the 

 larger pores. The fact was not at the time actually I'ealised, 

 that these were alcyonoid polyps ; there are also pinnately ten- 

 tacled annelids or worms, and this circumstance justified the con- 

 jecture that they probably represented the matured growth of the 

 undoulited worms which inhabited the more numerous smaller 

 pores. On raising the specimen nearer to the surface of the 

 water, for more careful examination, the anima.s retreated again 

 into their respective cells, and were seen no more in the living 

 state. Other engagements prohibited the further iuA^estigation 

 of the organism on this occasion, and it was placed in spirit for 

 future examination. 1 have recently satisfied myself that Pro- 



