ACORN-BAKNACLES. 5 



Let me suppose you are looking at my Aquarium. 

 Here I shew you a piece of stone, covered over, you 

 perceive, with white conical spots. The animals 

 which I inform you are represented by the spots do 

 not strike you as in any way remarkable, certainly 

 not for beauty. But have patience for a moment. I 

 have dropped the stone into the water. Let us look 

 at it after a few minutes have elapsed with a hand- 

 lens. Is not that a marvellous change ? Were you 

 prepared for such a beautiful sight? Each shell has 

 opened, and from each aperture " a fairy-like hand is 

 constantly thrust, grasping at some coveted object, 

 and then closed and withdrawn." 



But the object of this curious apparatus, however 

 beautiful in itself, is of a decidedly utilitarian cha- 

 racter. It is for the express purpose of ensnaring 

 such minute animalcules as may be within reach, to 

 " drag them down in the vicinity of the mouth, where, 

 being seized by the jaws, they are crushed and pre- 

 pared for digestion. No sense but that of touch is 

 required for the success of this singular mode of 

 fishing, and the delicacy with which the tentacles 

 perceive the slightest contact of a foreign substance, 

 shews that they are eminently sensible of tactile im- 

 pressions." * 



The following engraving represents four Barnacles 



attached to the shell of a Limpet. Two of them are 



" fishing," while the other two are in a passive state. 



Nearly the whole surface of the original Patella was 



* Rymer Jones's " Animal Kingdom." 



