PENNATmJK 



21 



Fig. 12. 



blance to a quill. It 

 consists of a calcareous 

 stem, the upper end of 

 which has a series of 

 branches on each side, 

 resembling the filaments 

 of a feather, and in the 

 end of each of which 

 resides an animal, the 

 whole being represented 

 by Fig. 12. Some of the 

 polypi are seen magnified 

 m Fig. 13. 



43. These animals are not fixed like those we have 

 described, but float along with the currents of the ocean, 

 having little or perhaps no power of locomotion, though 

 the movements of their tentacula are sufficient to prevent 

 their sinking, and to enable them to rise slowly in the 

 water. 



44. The pennatulse must be considered as a mass of. dis- 

 tinct animals aggregated together to form, in many respects, 

 one individual. In Botany, the class syngenesia presents 

 many distinct flowers assembled together to form a single 

 compound individual, as the thistle and dandelion, each 

 individual being on the same receptacle, and supported 

 by the same stem. So far, therefore as aggregation is 

 concerned, there is a strict analogy between a compound 

 flower and the pennatulse. But while each individual 

 of the syngenesian flowers receives its nourishment 

 through the same stem, the corresponding part of the 

 compound animal, which is a common stomach, receives 

 its nourishment through hundreds of mouths, so that here 

 the analogy fails. 



45. In the pennatulae, each mouth leads into a separate 

 stomach, whence the food, after digestion, passes into 

 several channels, which proceed in different directions 

 from the cavity of each stomach, dividing into many 

 branches, and being distributed over all the surrounding 

 portions of flesh. These branches communicate with sim- 

 ilar channels proceeding from the neighboring stomachs ; 



What is said of the stomach of the pennatulae ? 



