132 A NATUBALI8T IN CELEBES ch. vi 



bun, which I have not seen elsewhere on the TaUsse reefs. 

 There are also plenty of large Holothurians, the black 

 trepang of commerce for which these islands were at one 

 time famous, and the long snake-like Synapta, of a grey 

 mottled appearance. 



These and every other sign indicate that this part is 

 what I have previously called a ' vigorous reef,' the con- 

 ditions of the water ; the rapidity of the tides, the food 

 supply, or whatsoever it may be, are most favourable for 

 coral growth, and the reef is probably growing slowly but 

 surely seawards. 



Passing still further northwards, I find the reef gradually 

 diminishing in size and vigour, and before 1 have traversed 

 another quarter of a mile it has disappeared, the deep water 

 of the strait being close alongside of the sandy beach of 

 the shore. Curiously enough, this was the only part of the 

 reefs where I could find the bright green feather-stars. 



Eeturning now to the pier from which I started, and 

 wading in the opposite direction, I notice that the character 

 of the reef is rather different to that of the other side. It 

 is true there are to be fomid many of the same familiar 

 corals as before, but the specimens are, if anything, smaller 

 in size and more weakly in growth, and at the same time 

 there is a preponderance of soft fleshy creatures such as 

 Sponges, Alcyoniums, and Sarcophytums. None of the 

 sponges here grow to the enormous size they do in some 

 places, but some of them present the brightest colours that 

 are to be seen upon the reefs. One of them, I. can remem- 

 ber, was of a very brilliant orange colour, and others were 

 bright red and green. These colours are all soluble in 

 strong spirit. The shapes of the sponges are very varied ; 

 some form branching or multilobate masses not unlike the 

 Madrepores, others form solid clumps like puff-balls, while 

 others are but thin crusting lamellae on the surface of 



