Microscopical Essays. 



411 



lips gradually dilate, and adjuft themfelves accurately to the figure 

 of the prey. The greater! part of the animals on which the 

 polype feeds, are to it's mouth what an apple, the fize of our 

 heads, would be to the mouth of a man. 



The worms, &c. which are feized by the polype are not always 

 brought to the mouth in the fame fituation ; if they are prefented 

 to it by one of their extremities, it is not requifite that the polype 

 mould open it's mouth confiderably, and in effect it only opens 

 it fo wide, as precifely to give entrance to the worm, Fig. 5, 

 Plate XXIV. A. If it be not too long for the ftomach, it remains 

 there extended ; but if it be longer, the end which firft enters is 

 bent, fo that when the worm is entirely {'wallowed, it may be feen 

 lying folded in the ftomach, Fig. 12, Plate XXIV. B. 



If the middle, or any other part of the worm, be prefented to 

 the mouth of the polype, it feizes this part with the lips, extend- 

 ing them on both fides, and applying them again ft the worm, fo 

 that the mouth affumes the form of a boat, pointed at each end, 

 Fig. 2, Plate XXIV. A; the polype gradually clofes the two 

 points of it's boat-like lips, and by this motion and fuclion 

 {wallows the worm, Fig. 4, Plate XXIV. A, 



A worm is killed fo foon by a polype, that Mr. Fontana thinks 

 they mult contain the mod active and powerful venom ; for it's 

 lips fcarce touch the worm but it expires, lb great is the energy 

 of the poifon it conveys into it, though no wound can be obferved 

 in the dead animal. 



As 



