14 NATURAL HISTORY 



sessed of several distinct stomachs or digestive sacs; and 

 the latter such as have true alimentary canals and rotatory 

 organs provided with a number of cilia aptly disposed for 

 promoting the objects of life : these two grand divisions of 

 the Phytozoa are afterwards subdivided into families and 

 other minor branches, as exemplified in Book III. The 

 cilia, in their different combinations, supply the means of 

 locomotion, propelling the creature in many cases with 

 great rapidity through the water : they are apparently 

 stiff, like eye-lashes; and from Dr. E.'s description of 

 some of the larger ones, they issue from bulbous sub- 

 stances at their bases, and being acted upon by muscular 

 fibres are capable of being moved to and fro in particular 

 directions, so as to occasion a current of the fluid to flow 

 towards the mouth of the animalcule, by which it is fur- 

 nished with fresh water, or food. They are sometimes 

 disposed, as before stated, round certain organs of a cir- 

 cular form, which, on account of their peculiar vibra- 

 tions giving the appearance of a rotatory action, are 

 termed rotatory organs ; (see page 144) . A second cu- 

 rious feature in the construction of some of these minute 

 creatures are the setce, or bristles, attached to the surface 

 of their bodies : these short moveable hair& in all pro- 

 bability act as fins, and contribute greatly to their 

 means of motion. The third, feature are the uncini, or 

 hooks, setaceous appendages curved at their extremities, 

 and serving the creature to attach itself to any object it 

 chooses. A fourth are the stj/li, jointed at their bases, 

 and differing from the cilia in respect of their being 



