SANGUIFEROrS SYSTEM. 



char a. The colourless chyle derived from the food digested in 

 the stomachs of the polypi, and transmitted in successive por- 

 tions by the posterior orifice of these digestive sacs, is thus 

 circulated for the nutriment of each part of the system, with- 

 out the aid of the inert canals through which it moves. In the 

 larger polypi, as actiniae, the vibratile cilia are still more ob- 

 vious, propelling the currents and globules to and fro through 

 the body and the tubular tentacula of these animals, as the 

 digested fluids were seen by Trembly to pass through the body 

 and the long tentacula of the hydra. And even in the acalepha, 

 the fluids observed meandering through the motionless canals 

 of their transparent texture, appear to be impelled by the 

 same active agents. The thin serous fluid, replete with 

 globules, continues moving through the longitudinal la- 

 teral canals of the beroe pileus, while their parietes are 

 seen, through the transparent body of the animal, to 

 remain perfectly motionless, like the sides of the cells 

 of a plant. The same circulation of the nutritive fluids, 

 sent from the stomach, was observed by Eschscholtz in 

 the transparent canals of the cesium, and similar currents are 

 seen in the wide canals of the mantle in the aurelia (Fig. 113), 

 the rhizostoma, and all the larger medusae, but the minuter 

 filaments, every where distributed through their texture, ap- 

 pear to have no connection with the circulating system. The 

 currents of nutriment thus spread through every part of the 

 system in the lower radiated classes, serve alike to feed and 

 aerate their simple textures, in the same manner as the less 

 isolated currents through the homogeneous texture of pori- 

 phera. 



A more isolated sanguiferous system however, is seen in 

 the echinoderma, where a distinct set of vessels is appro- 

 priated to receive the colourless transparent chyle from the 

 alimentary cavity, and to convey it to the respiratory organs, 

 and thence through the rest of the body. These vessels are 

 especially obvious on the mesentery, which so commonly 

 suspends the intestine from the parietes of the abdomen in 

 the animals of this class, as in the echinus, spatangus, aste- 

 rias, holothuria, and allied genera, but no auricle or ventricle 

 is yet developed in their course, although Chiaje has assigned 

 these names to minute sinuses on the ends of the principal 

 vessel of the sipunculus. Fluids replete with globules, and 



