EPITOMES OF pia:matella repens. IGl 



to the spectacle of this wonderful apparatus, by 

 which water-currents are made to bathe the ten- 

 tacles, and assist respiration, and also to carry food 

 towards the mouth, over whicli a sort of linger or 

 tongue is stretched to guard the way, and exercise 

 some choice as to what particles shall be permitted 

 to pass on. This organ is called the episUmie, 

 from two Greek words, signifying ^'upon the mouth." 



If the cell is an old one, it may be covered with 

 so much extraneous matter as to obscure the economy 

 within ; but we are fortunate in having a transpa- 

 rent specimen before us, through which we can see 

 all that goes on. The alimentary tube, after forming 

 a capacious cavity, much longer than it is broad, 

 turns round and terminates in an orifice near the 

 mouth, and just below the integuments. When 

 refuse has to be discharged, this orifice is protruded; 

 and after the operation is over, it draws back as 

 before. Long muscles, composed of separate threads 

 or fibres, pull the creature in and out of its cell, 

 and at the part where the stomach ends, and the 

 intestine turns round, is attached a long flexible 

 rope, called the funiculus^ which goes to tlie bottom 

 of the cell. The passage of the food down to the 

 stomach, its digestion, and the eviction of the resi- 

 due, can all be watclied ; and when a large morsel 

 is swallowed, the spectacle is curious in the extreme. 



One day a polypide cauglit a large rotifer, (li. 



