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Microscopical Essays. 



As foon as the ftomach is filled, it's capacity is enlarged, the 

 body is fhortened, Fig. 6, Plate XXIV. A, the arms are for the 

 moft part contracted, the polype hangs down without motion, 

 and appears to be in a kind of flupor, and very different from it's 

 extended fliape ; but in proportion as the food is digefted, and it 

 has voided the excrementitious parts, the body lengthens, and 

 gradually recovers it's form. 



The tranfparency of the polype permits us to fee diftinclly the 

 worm which has been fwallowed, Fig. 12, Plate XXIV. B, which 

 gradually lofes it's form. It is at firft macerated in the ftomach 

 of the polype, and when the nutritious juices are feparated from 

 it, the remainder is difcharged by the mouth, Fig. 13. It is with 

 thefe as with other voracious animals, as they eat a great deal at 

 once, fo alfo they can fa ft for a long time. The hiftory of infects 

 furnifhes many examples of this kind. 



One circumftance is obfervable, which probably contributes 

 much to the digeftion of their food, namely, that the aliments are 

 continually pufhed back from one extremity to the other of the 

 ftomach ; this motion may be eafily obferved with a microfcope, 

 in a polype which is not too full, and in which the food has been 

 already divided into little fragments. For thefe obfervations, it is 

 beft to feed the polype with fuch food as will give a lively- 

 coloured juice ; as for example, thofe worms whofe inteftines are 

 filled with red fubftances : for by this means we fhall fee that 

 the nutritious juices are conveyed not only to the extremity of 

 the body, but alfo into the arms, from whence it is probable that 

 each of the arms form alfo a kind of gut, which communicates 

 with that of the body. Some bits of a fmall black fnail, that is 



frequently 



