26 A NATUBALI8T IN CELEBES 



times with considerable rapidity, the corals are not growing 

 vigorously and well, and in many other places I could refer 

 to I found that luxuriant coral growth is not consistent 

 with very lively water. 



Again, in deep bays or inlets, where tidal and ocean 

 currents are scarcely felt, there is but little vigour in the reef, 

 and the presence of fresh-water streams entirely destroys 

 all the coral Hfe upon it. The best places for the collector 

 and observer of these forms are always to be found at the 

 sides of reefs or promontories which project some distance 

 into the sea. 



It is not difficult to find an explanation of the fact that 

 corals will not grow in very rapid water. In the first place, 

 their food, whatever it may be, cannot be easily captured 

 when it is rushed past them as in a millstream ; and in the 

 second place, the embryos which they discharge are carried 

 away by the currents into less lively waters, where they can 

 fix themselves upon the reef and grow. 



It would not, I think, be a very difficult thing to determine 

 with some considerable accuracy the rapidity of the current 

 most favourable for coral growth, but, to be trustworthy, 

 the observations must be undertaken by a naturalist who 

 is familiar with the fauna of the coral reefs, assisted 

 by practical seamen who are competent to determine 

 the rate of tidal currents, and have the command of 

 steam. 



The result of such an investigation would not only be 

 of considerable interest to scientific men, but would in aU 

 probability lead to several important cautions to the navi- 

 gators of coral seas. 



Vessels are constantly being lost upon coral reefs in 

 different parts of the world,' and many accidents are due to 



' Two sailing-ships were lost on the coral reefs near Manado during the 

 eleven months I was in Celebes. 



