160 CRUISE OF THE BARRERA 



To make an "accident" still worse, these spines 

 are more or less bedaubed with a slimy acrid sub- 

 stance which acts as a powerful irritant. From 

 a slight wound on the hand one may suffer pain 

 even to the shoulder and for some moments actu- 

 ally feel faint. While these spines may not be 

 extracted, they do eventually absorb and disap- 

 pear. One experience, however slight, with a 

 diadema, is quite sufficient to inspire great respect 

 for them ever after. During the hours of bright 

 sunshine the diademas seek cover under the rocks 

 and coral masses, and their presence is betrayed 

 only by occasional tufts of their bristling bayo- 

 nets that project here and there from beneath their 

 hiding-places. In the late afternoon when the 

 slanting rays of the sun illumine the reef bottom 

 less brightly, they issue forth en masse in search of 

 food and probably continue their slow wanderings 

 throughout the night. In localities where hiding- 

 places are few, such as upon sandy patches in or 

 near a reef, the diademas are always more or less 

 in evidence. No protective covering — short of a 

 steel armor — would offer any real security. Con- 

 stant vigilance and care, when entering their 

 domain, is the only safeguard. 



