46 THE MICROSCOPE. 



scarcely a more interesting object for contemplation. 

 Search for these creatures in mill-pools and ponds 

 through which a current of water gently flows. If a 

 portion of water-weed be brought home and placed in 

 a glass vessel, and the leaves of the plants be care- 

 fully examined with a lens the long thread-like leaves 

 of the water crowfoot (Ranunculus aquatilis) are a very 

 favourite habitat you will probably detect delicate 

 projecting objects of a reddish-brown colour, light or 

 dark, however, according to the nature of the bottom 

 of the pool. These are the tubular cases of Meliccria. 

 If one of these, still attached to the bit of weed, be 

 placed on a slip of glass, and viewed under the micro- 

 scope with a power of about 50 diameters, you will 

 notice that this tube is made of several series of round 

 clay or mud pellets. By-and-by, if you will be careful 

 not to shake the table on which the specimen is 

 placed (for Mdicerta is a coy and timid creature), you 

 will see the occupant slowly unfold the anterior portion 

 of its body from the orifice of the tube. At first, as 

 Mr. Gosse has well described it, "a complicated mass 

 of transparent flesh appears involved in many folds, 

 displaying at one side a pair of hooked spines, and at 

 the other two slender truncate processes projecting 

 horizontally. As it exposes itselt more and more, 

 suddenly two large rounded discs are expanded, 

 around which at the same time a wreath of cilia is 

 seen performing its surprising motions. Often the 

 animal contents itself with this degree of exposure, 

 but sometimes it protrudes further, and displays two 

 other smaller leaflets, opposite to the former, but in 

 the same place, margined with cilia in like manner. 

 The appearance is now not unlike that of a flower of 

 four unequal petals ; from which resemblance Linnaeus, 

 who compared it to a ringent labiate corolla, gave it 

 the trivial name of ringens, by which it is still known.'* 



