FROM A POXI), AND THEIR TENANTS. 169 



the ciliary currents in such a manner as to throw a stream of 

 small particles into the mould, which is a muscular organ secreting 

 a cement by which they are joined together. When a pellet is 

 completed, the creature bends down its body and deposits it in 

 its proper ])lace, and this goes on day by day until the tower is 

 finished and the creature dies. 



This animal increases by means of eggs which are hatched in 

 the tower. Soon after its birth, the young builder is thrown over- 

 board, as it were. It then bears something of a resemblance to 

 the common rotifer, and swims about rapidly as if rejoicing in its 

 liberty. After a short time, however, it selects a suitable site for 

 its future habitation, and then, having first constructed, as a 

 temporary dwelling, a glass-like tube, commences the erection of 

 its marvellous tower. 



Our third object is the " Stephanoceros," or "crowned animal- 

 culae." This exquisitely beautiful creature is about the thirty- 

 sixth part of an inch in length. It is enclosed in a transparent 

 tube, over which it extends its five long arms in a graceful 

 manner. These arms, as will be seen, are furnished with rows of 

 short cilia, which enable the creature to retain the prey brought 

 within their grasp until it is swallowed. At the least danger these 

 arms are withdrawn into the sheath. The body in our specimen 

 resembles a crystal cup, and the food, composed of small red and 

 green coloured bodies, adds to the lustre of this remarkable 

 creature. Often an egg or two may be seen attached to the 

 parent, and the young, when hatched, speedily settle down the 

 same as in the previous instance. These animals are frequently 

 to be found on some of the branches of small water-plants, and 

 are capable of being preserved for some weeks if placed in a 

 suitable tank with a proper supply of fresh water. 



Let us now turn our attention to another species of animal- 



culae, Vorticelli, which is to be found in most country ponds, and 



not unfrequently in our aquariums. These creatures are of 



various sizes, some being so large that their presence can almost 



be detected with the naked eye, and others so minute as to 



require one of the high powers of our microscope to reveal all 



their structure. They bear a striking resemblance to a cup in 



form, and their bodies are placed upon a long stalk, which has the 



Journal of Microscopy and Natural Science. p 



New Series. Vol. II. 1889. 



