SECT. IV. 



ACTINIA. 



Fig. 129. Actinian polype. 



sembles a blossom. The soft smooth, body consists of 

 two layers, as may be seen in the sections of an Actinia 

 (fig. 129). The outer layer generally contains red 

 matter, the inner /& 



one is of muscular 

 iibre, and contains 

 a great cavity, in 

 which a somewhat 

 globular bag or 

 stomach is sus- 

 pended. The space 

 between the sto- 

 mach and the 

 cylindrical body 

 of the animal is 

 divided in to cham- 

 bers by perpen- 

 dicular radiating 

 partitions, consisting of thin plates or lamellae. The 

 mouth, which opens at once into the stomach, imbibes 

 sea-water ; and the hollow tentacles surrounding it 

 being perforated at their extremities, and in communi- 

 cation with the chambers immediately below them, also 

 imbibe the sea-water and convey it into the chambers ; 

 and the vibrations of the innumerable cilia, with which 

 all the cavities of the animal are lined, keep them per- 

 petually bathed with the respiratory medium mixed with 

 nutrient juices from the coats of the stomach. 9 



The Sea Anemone is monoecious and oviparous ; the 

 eggs are formed and fertilized in the lower parts of the 

 perpendicular lamellse or radiant plates ; but they are 

 hatched within the visceral cavity, and the larvse issue 

 from the mouth. The Actiniae are also propagated by 

 buds. They have as great a power of repairing injuries 

 as the Hydrse, and like them too, though generally fixed, 



9 ' Lectures on Comparative Anatomy,' by Professor Owen. 

 K 2 



