114 F. W. PHIXLIPS OBSERVATIONS ON ROTIFERS. 



a compressorium. But we will leave this, and all other disputed 

 points, for the consideration of specialists. This wheel-like motion 

 does not exist in all rotifers, for the movement of the cilia is often 

 confined to short quivering vibrations. When the creature is at 

 rest, or is alarmed, it withdraws its head and tucks its wheel into 

 its body, and then assumes a spindle shape ; its movements are now 

 very much like those of a leech, groping about in all directions : 

 but after a time the head issues forth again and the wheels resume 

 their action. 



Few things are more strikingly beautiful than this ciliated wreath 

 in full activity. Sometimes it is used as a locomotive organ, pro- 

 pelling the creature rapidly through the water; and when the 

 rotifer moors itself to a piece of weed, it is used as a feeding organ, 

 making a vortex in the surrounding water, and thus causing all 

 particles to rush into its mouth. The food, which is thus drawn 

 in, passes down an alimentary canal into the gizzard. This canal 

 has unfortunately received a variety of names: oesophagus, pharynx, 

 vestibule, infundibulum, and buccal funnel ; but we will select 

 the word "pharynx," as being the most suitable. The pharynx 

 terminates at, and partially embraces, the masticating apparatus, or 

 " mastax " as it is called, which consists of a miiscular bulb, con- 

 taining a pair of organs called " mallei," from their resemblance to 

 hammers working on an anvil. Each malleus is divided into two 

 parts, the "manubrium" and the "uncus"; these are articulated 

 together by a hinge- joint, and are placed nearly at right angles to 

 each other ; the former, as its name implies, serves the purpose 

 of a handle, and the latter grinds and crushes the food. This is 

 done by several finger-like processes at the extremity of the unci, 

 which are placed parallel to each other, something like the teeth 

 of a comb ; the food then, after passing down the pharynx, is 

 received by the unci, which reduce it to atomic particles. The 

 motion of these jaws, which, owing to the extreme transparency 

 of the creature, may be clearly seen, is so regular and constant 

 that they cannot tail to impress the observer with a sense of 

 mechanical power, and, as some writer has observed, " one might 

 easily imagine that the sound of the jaws could be heard." The 

 refuse of matter which is thus digested passes down an intestinal 

 canal, and is voided by a very distinct anal orifice. In one genus 

 [Asplanchna) this is wanting, and the effete matter is ejected 

 through the mouth. Just below the wheels are two bright red 

 spots, which are now admitted by most naturalists to be the 

 eyes. In some species their colour changes to a violet or black 

 as the creature grows older. The eyes vary in number from one 

 to eight, sometimes they are entirely wanting and sometimes 

 very prominent. 



Mr. Bedwell, referring to Bhinops vitrea, says: "The eyes, when 

 seen on a black ground, are simply diabolical, they glare at you 

 like two railway lamps sailing about." Just beside the eyes may 

 be seen a mass of matter which is supposed to be nervous, and 

 the analogue of a brain, but observers are very much divided in 



