24 BRICK-MAKING EXTRAORDINARY. 



attached by a long pedicle or foot-stalk, above which is the body 

 of the animal, of an oval form, and surmounted by five long 

 tentacles, beset with tufts of bristly cilia. This beautiful Roti- 

 fer is of common occurrence, attached to aquatic plants, in ponds 

 of clear water, and seen with a good light it is an object of which 

 the observer never grows weary. More curious, perhaps, but 

 less beautiful, is another of these sessile Eotifers, which inhabits 

 a tube built up, particle by particle, by its own unwearied industry. 

 The Melicerta ringens is a bom brick-maker, and no sooner starts 

 in life as a respectable stay-at-home member of the great Rotifer 

 family, than he proceeds forthwith to build himself a house in 

 which to spend his days. The first step in the process, it appears, 

 is to exude from the body a delicate gelatinous cylinder to serve 

 as a sort of framework on which the more substantial structure 

 is to be formed. This accomplished, the brick-making skill of 

 the Melicerta is at once in request. Beneath a projection on the 

 animal's head there is a small disc-like organ, which, when 

 the ciliary lobes are in full play, revolves like the circular 

 ventilator of a window. This is the brick-making machine ; 

 and the animal so modifies the direction of the ciliary currents, 

 as to send into it most of the solid particles which are drawn 

 from the surrounding water. Here they are worked up, pro- 

 bably with some peculiar glutinous secretion, and moulded into 

 little globular pellets ; and no sooner is each pellet completed than 

 the animal bends down its head, and applying the pellet-disc to 

 the edge of the tube, deposits the newly-formed brick in its ap- 

 propriate place. The finished tube consists of many hundreds of 

 such bricks, and as each of them usually occupies about three 

 minutes in making, including the collection of the materials, it 

 is obvious that the Melicerta has no small amount of work to 

 get through before it can complete its dwelling. It makes no 

 undue haste, however, and its work is finished off with a neat- 

 ness and regularity which are truly admirable. 



A very extraordinary circumstance connected with the Ro- 

 tifera is their power of becoming revivified, after remaining for a 

 considerable period dried up, and apparently dead, on being again 

 moistened with a few drops of water. This extreme tenacity of 

 life is so truly remarkable, that it has excited much attention, 

 and led to many curious experiments. Fontana, an Italian 

 naturalist, kept a number of the animalcules for two years and 



