182 THE MICROSCOPE. 



but can detach themselves at pleasure ; whilst others are so intimately 

 joined and connected together, that no one seems capable of moving or 

 changing place without affecting the quiet and situation of all the rest, 

 But this creature forms as it were an intermediate gradation between 

 the other two, dwelling in the same general habitation with others of 

 its own species, from whence it cannot entirely separate itself; and yet 

 therein it appears perfectly at liberty to exert its own voluntary 

 motions; and can either retire into the common receptacle, or push 

 itself out from thence, and expand its curious members, without inter- 

 fering with or disturbing its companions. 



" They dwell together from the numbers of ten to fifteen (seldom 

 exceeding the latter or falling short of the former number), in a filmy 

 kind of mucilaginous or gelatinous case, which out of the water has no 

 determined form, appearing like a lump of slime ; but when expanded 

 therein, resembles nearly the figure of a bell with the m.outh ui)wards, 

 and is usually about the length of half an inch, and one quarter of an 

 inch in breadth or diameter. This case being very transparent, all the 

 motions of its inhabitants may be discerned through it distinctly. It 

 seems divided internally into several apartments, or rather, to contain 

 several smaller saccidi, each of which encloses one of these animals. 

 The openings at the tops of these saccuK axe but just sufiicient to admit 

 the creature's head, and a very small part of its body, to be thrust 

 beyond them, the rest remaining always in the case. The animal can, 

 however, when it pleases, draw itself down entirely within the case, 

 which is an asylum to secure it from its enemies (for it is not unlikely 

 many of the larger aquatic insects prey upon it). , 



" The arms are set round the head to the number of forty, having 

 each the figure of a long/, one of whose hooked ends is fastened to its 

 head; and altogether, when expanded, compose a figure somewhat of 

 a horse-shoe shape, convex on the side next the body, but gradually 

 opening and turning outwards, so as to leave a considerable area within 

 the outer extremities of the arms. And when thus extended, by giving 

 them a vibrating motion, the creature can produce a current in the 

 water, which brings the animalcules, or whatever other minute bodies 

 are not beyond the sphere of its action, with great velocity to its 

 mouth, whose situation is between the arms ; where they are taken in 

 if liked, or else, by a contrary current, which the creature can excite, 

 they are carried away again; whilst at the same time other minute 

 animalcules or substances that, by lying outside the enclosure made by 

 the arms, are less subject to the force of the stream, are seized by 

 them ; for their sense of feeling is so exquisite, that on being touched 



