286 Characteristics of Rotifers. 



compared to the whiskers of the cat — they are collectors of a 

 certain sort of inform ation, not apparatus for catching food. If 

 any object strikes rudely against the long hairs of the Flos- 

 cule, she returns to her cell ; and shaking the table will often 

 induce her to do the same. 



Let us now look at the Stephanoceros , the finest of all roti- 

 fers when seen in perfection, and a most voracious creature. 

 Her cup-shaped body often seems nearly filled with green and 

 golden monads and similar things she has swallowed. The 

 dark ground illumination of the parabola or spot lens, in such 

 cases, makes the creature look like a crystal goblet filled with 

 emeralds and rubies. The five arms are something like the 

 tentacles of the polyzoa, and they bear cilia at their edges. A 

 little examination, however, shows us that the Stephanoceros arm 

 cilia are not like those of a polyzoon in constant vibration, but 

 more quiescent, like those of the Floscule. They are also much 

 longer than those of the polyzoa — indeed, much longer than 

 any of the drawings in ordinary books represent them, and 

 much longer than any microscopist will have a chance of see- 

 ing them, who does not take great care of his illumination. 



In Melicerta we come back to the wheel cilia, but the most 

 noticeable peculiarity of this creature is her method of building 

 her tube, which Mr. Grosse was the first to describe, though 

 she was known to Leuwenhoek in 1703. Immediately below 

 the angular chin of the Melicerta is a cup-like organ to which a 

 ciliary current can bring particles to be " moulded with the help 

 of some secretion into the pellets of which the little house is 

 built up. Having formed her brick the Melicerta bends her 

 head and deposits it in its place.'" 



The tubes of the rotifers we have just considered are 

 constructions, that of the Melicerta being an example of 

 masonry, while those of Floscnle and Stephanoceros are simpler, 

 consisting of a gelatinous-looking exudation thrown off by 

 the animal in the form of rings. In the case of Stephanoceros 

 the successive portions are roughly joined, so that the divisions 

 may be seen in the tubes of this species. In Limnias and 

 OEcistes the tubes are gelatinous in aspect, and sticky on the 

 outside, so as to cause the adhesion of extraneous particles. 

 In the Floscnle, the gelatinous-looking matter, whatever may 

 be its chemical composition, is a very perfect transparent 

 hydraulic cement, and the structure it forms is so thin and 

 transparent as to be very easily overlooked. 



If we pass from these tube- dwelling rotifers to the asso- 

 ciated rotifers Conor/til '".'<■ and Lacinularia we do not find 

 anything that can be fairly termed a tube. The rounded 

 balls which they present to our notice, are composed of 

 individuals moro or less immersed in a gelatinous mass, 



