ITS CILIATED TENTACLES. 115 



whole animal appears white, a translucent white. This 

 is a very lovely variety. Still, even in these, the hues 

 I have mentioned ahove may in general be faintly 

 traced. 



I am not aware that any naturalist has recorded an 

 interesting peculiarity, that I have observed in the 

 tentacles. It is that their surface is delicately ciliated. 

 I was examining one with a rather low power, when I 

 thought I saw something like a current in the water 

 over the tentacles. I immediately put on a power of 

 140 diameters, which was but just sufficient to show 

 it distinctly ; I was precluded from the use of a higher 

 power by the nature of the vessel in which the speci- 

 mens were kept. However I unmistakeably saw 

 minute atoms slowly moving in the water come into 

 proximity to a tentacle, then immediately whirled 

 along with rapidity in the direction of the point ; the 

 same thing was seen on both sides of the tentacle, and 

 in fact all over its surface, the direction being in all 

 cases the same, from the base towards the point. I 

 tried many tentacles, and two specimens of the Madre- 

 pore, with precisely the same result. I saw a very 

 minute atom, hurled along close to the surface, rise 

 over the warts and descend into the hollows between 

 them, so as to show that the cilia clothe both the 

 warts and the plain surface of the tentacle. The 

 globular tip, however, I think is destitute of them, for 

 though the atoms were often hurled partly round this, 

 I believe it was only by the impetus already acquired, 

 for I could never see any motion either originated or 

 undeniably continued there. The cilia themselves I 

 could not detect by the most delicate manipulation. 



