302 TOILERS IN THE SEA. 



at the corner of each cell, with a long and slightly 

 curved bristle, which is fixed at the lower end by a 

 joint. It terminates in the finest point, and has its 

 outer, or convex, side serrated with delicate teeth or 

 notches. Having placed a small piece of a branch 

 under the microscope, I was exceedingly surprised 

 to see it suddenly start from the field of vision, by 

 the movement of these bristles, which acted as oars. 

 Irritation generally produced this motion, but not 

 always. When the coral was laid flat on that side 

 from which the toothed bristles projected, they were 

 necessarily all pressed together and entangled. This 

 scarcely ever failed to excite a considerable move- 

 ment among them, and evidently with the object of 

 freeing themselves. In a small piece which was 

 taken out of water, and placed on blotting-paper, the 

 movements of these organs were clearly visible for a 

 few seconds by the naked eye. 



" In the case of the vulture-heads, as well as in 

 that of the bristles, all that were on one side of the 

 branch, moved sometimes co-instantaneously, some- 

 times in regular order, one after the other ; at other 

 times the organs on both sides of the branch moved 

 together ; but generally all were independent of each 

 other, and entirely so of the polyps. If the bristles 

 were excited to move, by irritation, in any one 

 branch, generally the whole zoophyte was affected. 

 In the instance where the branch started from the 



