POLYPI. 417 



CLASS XIII. POLYPI, Cuv. Lam. 



Gelatinous animals, with elongated contractile body, and an ali- 

 mentary sac with one opening ; mouth distinct and termi- 

 nal^ surrounded with tentacula or radiated lobes ; the great- 

 er number adhering together, and forming compound ani- 

 mals. 



* 



THE class of Polypi or Zoophytes is one of the largest and 



most singular of the Animal Kingdom. Nearly at the lowest step 

 in the animal scale, many of them have the form of plants, ac- 

 companied by the simplest organization of parts for a living being 

 capable of reproduction. Destitute of head and eyes, and hav- 

 ing no organs for circulation, respiration, or locomotion, the bo- 

 dy of the Polypus appears only as .a homogeneous substance, con- 

 stituted of gelatinous and irritable cellular tissue, in which the 

 fluids essential to life move sluggishly. All are, however, fur- 

 nished with an internal cavity or stomach, with faint traces in 

 some of hollow canals and ovaries. The body is generally cy- 

 lindrical or conical, gelatinous or transparent ; and the mouth, 

 surrounded by tentacula varying in number and form, serves 

 also for anus. Many of the polypi have the principle of life 

 so diffused in their simple structure, that portions cut from 

 the individual soon acquire in the proper element all the cha- 

 racters of the perfect animal. Most of the same species, be- 

 sides, form compound animals, adhering to one another by la- 

 teral appendages, or by their posterior extremity, and partici- 

 pate in a common life without ceasing to enjoy their individual 

 and independent existence. The mode of reproduction in 

 many individuals of this class is unknown. In general, it 

 may be remarked, that many are conceived to be gemmiferous, 

 or to extend the race by buds in the manner of plants, while 

 others propagate the species by means of ova. In the lowest of 

 the races the distinctive characters of animal life are so faintly 

 drawn, that with difficulty can many of these be distinguished 



the Cryptogamic families of the Vegetable Kingdom. 

 VOL. a. D d 



